Purple Birthday Cake – Soft Vanilla Layers with Lavender Buttercream

Let’s Bake Some Birthday Magic!

Hey friends, Beau here! Is there anything in the world that sings “celebration” quite like a homemade birthday cake? I don’t think so. That moment when you carry it out, candles flickering, and everyone’s face lights up… it’s pure, edible joy. But today, we’re not making just any cake. We’re making a Purple Birthday Cake—a towering, dreamy, lavender-hued masterpiece that’s as fun to make as it is to devour.

This isn’t about complicated techniques or hard-to-find ingredients. This is about soft, fluffy vanilla layers that taste like a cloud, wrapped in the creamiest vanilla buttercream we’ve ever tinted a glorious shade of purple. It’s whimsical, it’s nostalgic, and it’s guaranteed to be the star of the party. Whether you’re baking for your kiddo, your best friend, or just because you deserve a slice of purple happiness (the best reason!), this cake is your project. So tie on your favorite apron, crank up some good tunes, and let’s get ready to create something spectacular. This is more than baking; it’s making a memory, one delicious layer at a time.

Why Purple? A Little Slice of My Story

Let me take you back to my 8th birthday. My mom, the queen of kitchen adventures, asked me what color I wanted my cake to be. “Purple!” I yelled, without a second thought. Not blue, not red. Purple. The color of grapes, of twilight sky, of my favorite cartoon dinosaur (Barney, I’m looking at you). What I remember isn’t just the cake—it was the look of sheer determination on her face as she whisked and dripped food coloring, creating a batter that looked like lilac soup. The final product was a lopsided, deeply violet two-layer cake with slightly gray frosting (a lesson in color theory we’d later master!). But to me, it was the most magnificent thing I’d ever seen. It tasted like love and a little bit of food coloring. That cake taught me that food is about personality. It’s about injecting a piece of who you are, or who you’re celebrating, right into the recipe. That’s the spirit we’re bringing today. We’re going for that same wow-factor, but with a few pro-hacks to make sure our purple is vibrant and our frosting is flawless. Let’s make that magic!

Gathering Your Purple Party Ingredients

Here’s everything you’ll need to build this beauty. I’ve added my little chef notes next to each one because knowing your ingredients is half the battle won!

For the Cake Layers:

• 2½ cups all-purpose flour: The trusty foundation. Spoon and level it into your measuring cup to avoid a dense cake. For a slightly softer crumb, you can swap ½ cup with cake flour.
• 2½ teaspoons baking powder: Our lift and fluff agent. Make sure it’s fresh for maximum rise! Give the can a sniff—it should smell sharp, not dull.
• ½ teaspoon salt: The flavor enhancer. It balances all the sweetness and makes the vanilla pop. Never skip it!
• ¾ cup unsalted butter, softened: This is where flavor and texture begin. “Softened” means it yields to a gentle press but isn’t oily. Leave it out for 45-60 minutes. For dairy-free, a high-quality plant-based butter works great.
• 1¾ cups granulated sugar: Sweetness and, importantly, it helps create a tender crumb by creaming beautifully with the butter.
• 4 large eggs, room temp: The binding superstars. Room temperature eggs incorporate much more smoothly, giving you a uniform, lofty batter. Place them in warm water for 5 minutes if you forgot to take them out!
• 1 tablespoon vanilla extract: Go for the good stuff! Pure vanilla extract makes all the difference. This is a whole tablespoon for major cozy flavor.
• 1 cup whole milk, room temp: Moisture and tenderness. Whole milk gives the best richness, but 2% will work. Again, room temp is key for even mixing.
• Purple gel food coloring: The star of the show! I insist on gel over liquid. It’s more concentrated, so you get vivid color without watering down your batter. Start with a little—you can always add more!

For the Lavender Buttercream:

• 1½ cups unsalted butter, softened: Yes, more butter. This is buttercream, my friends, and it’s going to be silky, dreamy, and perfect for piping.
• 5 cups powdered sugar, sifted: Sifting is non-negotiable here. It prevents lumps and makes the frosting irresistibly smooth.
• 2 teaspoons vanilla extract: Keeping the flavor consistent and delightful.
• 3–4 tablespoons heavy cream or milk: This is your texture control. Start with 3, add the 4th if you want a slightly softer, more spreadable frosting.
• Purple food coloring: Use the same gel coloring. For a cool ombré effect, you can divide the frosting and tint each portion a different shade.

Optional Decorations:

Go wild! Sprinkles, edible glitter, silver dragees, piped buttercream rosettes, fresh flowers, or a simple “Happy Birthday” scrawled in white chocolate. It’s your canvas!

Let’s Build This Beautiful Beast: Step-by-Step

Follow these steps, read my little asides, and you’ll have a flawless cake. Promise!

1. Prep Like a Pro. Preheat your oven to 350°F (175°C). Grease three 8-inch round cake pans with butter or baking spray, then line the bottoms with parchment paper circles. This duo guarantees a clean release every single time. Trust me, the parchment is your best friend.
2. Whisk the Dry Team. In a medium bowl, whisk together the flour, baking powder, and salt. This isn’t just mixing; it’s ensuring our leavening is evenly distributed so every bite is perfectly risen. Set this aside.
3. Creaming is Key. In your stand mixer or a large bowl with a hand mixer, beat the softened butter and granulated sugar together on medium-high speed for a full 3-4 minutes. We’re not just combining them; we’re aerating the mixture until it’s pale, fluffy, and almost white. This step builds the cake’s structure and tenderness. Scrape the bowl down once halfway through.
4. Egg-cellent Incorporation. With the mixer on medium, add the eggs one at a time, letting each fully blend in before adding the next. Add the vanilla with the last egg. This patience prevents the batter from breaking or curdling. It should look gloriously smooth and emulsified.
5. The Alternating Dance. Reduce mixer speed to low. Add about one-third of your flour mixture, mix until just combined. Follow with half the milk. Repeat with another third of flour, the rest of the milk, and finish with the final third of flour. Mix each addition only until the streaks disappear. Overmixing at this stage develops gluten and leads to a tough cake. Be gentle!
6. Paint it Purple. Now for the fun! Add your purple gel food coloring a few drops at a time. Fold or mix on low until you achieve a uniform, dreamy lavender batter. Remember, the color will bake slightly darker. Pour the batter evenly into your three prepared pans and smooth the tops.
7. Bake to Perfection. Bake for 25-28 minutes. Rotate the pans halfway through for even baking. They’re done when the tops spring back lightly to the touch and a toothpick inserted in the center comes out with a few moist crumbs (not wet batter).
8. The Patience Phase. Let the cakes cool in their pans on a wire rack for 10 minutes. Then, run a knife around the edges, invert them onto the rack, peel off the parchment, and let them cool completely. I repeat: completely. Frosting a warm cake is a recipe for a melting, sliding mess.
9. Whip Up the Buttercream. While cakes cool, make the frosting. Beat the softened butter on medium speed for 2-3 minutes until it’s smooth and creamy. Gradually add the sifted powdered sugar, one cup at a time, on low speed (unless you want a sugar cloud!). Add vanilla and 3 tablespoons of cream. Beat on medium-high for 2-3 minutes until incredibly light and fluffy. Tint with purple gel coloring. If it’s too thick, add the extra cream.
10. Assemble Your Masterpiece. Place one cake layer on your serving plate or turntable. Spread a generous, even layer of buttercream. Repeat with the second layer. Top with the third layer. Apply a thin “crumb coat” of frosting all over the cake, then chill for 15 minutes to lock in crumbs. Finally, pile on the remaining frosting and smooth or swirl it to your heart’s content. Decorate and celebrate!

How to Serve This Showstopper

Presentation is part of the joy! For clean slices, dip your sharp knife in hot water and wipe it dry between each cut. This gives you beautiful, crisp layers in every piece. Serve on simple, elegant plates to let the purple really shine. A scoop of vanilla bean ice cream or a dollop of whipped cream on the side is never a bad idea. And of course, don’t forget the candles—sparkly ones, number candles, or a whole forest of them! The goal is to make the moment as special as the cake itself. Pour the milk, gather your people, and get ready for the “oohs” and “aahs.”

Make It Your Own: Fun Variations

Love the purple vibe but want to mix it up? Here are some delicious twists:

• Purple Velvet: Add 2 tablespoons of black cocoa powder or regular cocoa powder to the dry ingredients for a subtly chocolatey, deeper purple hue with that classic velvet tang.
• Lemon-Lavender: Add the zest of two lemons to the cake batter and swap the vanilla in the frosting for 1 teaspoon of culinary lavender extract (use sparingly!). It’s floral, bright, and incredibly elegant.
• Funfetti Inside! Fold ½ cup of rainbow sprinkles (jimmies, not nonpareils) into the purple batter before dividing into pans. The colorful surprise inside is a total party!
• Dairy-Free & Vegan: Use plant-based butter and milk, and replace each egg with a flax egg (1 tbsp ground flax + 2.5 tbsp water per egg). The color and fun remain 100% intact.
• Ombré Frosting: Divide your buttercream into three bowls. Leave one white, tint one light purple, and one dark purple. Frost the cake with the darkest at the bottom, graduating to white at the top for a stunning sunset effect.

Beau’s Back-Pocket Tips & Stories

This recipe has seen a few iterations in my kitchen. The first time I made it for the blog, I got over-zealous with the gel coloring and ended up with what my nephew lovingly called a “Galaxy Grimace Cake.” It was… intensely purple. Lesson learned: a little gel goes a long way! Start with a toothpick dip of color. Also, I used to just do two thick layers, but splitting it into three thinner layers not only looks more impressive, it gives you that perfect frosting-to-cake ratio in every bite. One last thing: if your kitchen is warm and the buttercream feels soft, don’t panic. Just pop the bowl in the fridge for 10 minutes, then re-whip. Baking is about the journey, laughs, and delicious adjustments along the way.

Your Questions, Answered

Q: Can I make this cake ahead of time?
A: Absolutely! You can bake the layers up to 2 days ahead. Let them cool completely, wrap each tightly in plastic wrap, and store at room temp. You can also frost the entire cake and refrigerate it (covered) for up to 24 hours before serving. Let it sit at room temperature for an hour before serving for the softest texture.

Q: My cake layers domed in the middle! How do I get them flat?
A: A slight dome is normal, but for perfect layers, try using cake strips! You soak fabric strips in water, wrap them around the outside of the pan, and they insulate the edges so the cake bakes evenly. No strips? Just use a serrated knife to carefully slice the dome off each cooled layer to create a flat surface. (Chef’s snack time!)

Q: Why did you specify gel food coloring?
A: Liquid food coloring is mostly water. To get a vibrant purple, you’d need so much that you’d throw off the liquid balance of your batter or frosting, potentially making it runny or affecting the bake. Gel color is potent, so you use less and get a bold, beautiful color without compromise.

Q: My buttercream looks grainy or curdled. Help!
A: This usually means your butter was too cold or the ingredients weren’t fully incorporated. The fix is easy: keep beating! Turn your mixer to medium-high and let it whip for another 3-5 minutes. The friction and continued emulsification will almost always bring it back to smooth, silky perfection.

Purple Birthday Cake

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• Author: BeauCollier

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Description

This Purple Birthday Cake is a fun, colorful celebration cake with soft vanilla layers and creamy purple buttercream. It looks impressive but uses basic baking steps and easy ingredients. Perfect for birthdays, parties, or anytime you want a cheerful showstopper.

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Ingredients

Scale 1x2x3x

Vanilla Cake Layers

• 2½ cups all-purpose flour

• 2½ tsp baking powder

• ½ tsp salt

• ¾ cup unsalted butter, softened

• 1¾ cups granulated sugar

• 4 large eggs, room temperature

• 1 tbsp vanilla extract

• 1 cup whole milk, room temperature

• Purple gel food coloring

Lavender Buttercream (Purple Vanilla Frosting)

• 1½ cups unsalted butter, softened

• 5 cups powdered sugar, sifted

• 2 tsp vanilla extract

• 3–4 tbsp heavy cream or milk

• Purple gel food coloring

Optional: sprinkles, edible glitter, piped decorations

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Instructions

1️⃣ Prep

• Heat oven to 350°F (175°C).

• Grease and line three 8-inch round pans with parchment.

2️⃣ Mix Dry Ingredients

• Whisk flour, baking powder, and salt in a bowl. Set aside.

3️⃣ Cream Butter & Sugar

• Beat butter and sugar 3–4 minutes until pale and fluffy.

4️⃣ Add Eggs & Vanilla

• Add eggs one at a time, mixing well after each.

• Mix in vanilla.

5️⃣ Combine Wet & Dry

• Mix in flour mixture and milk in this order:
  flour → milk → flour → milk → flour

• Mix just until combined.

6️⃣ Color the Batter

• Add purple gel coloring a little at a time until you reach your shade.

7️⃣ Bake

• Divide batter evenly between pans.

• Bake 25–28 minutes until a toothpick comes out with light crumbs.

• Cool 10 minutes in pans, then turn out and cool completely.

Notes

• Lemon Purple Cake: Add lemon zest to batter.

• Funfetti Purple: Stir in ½ cup rainbow sprinkles.

• Ombre Frosting: Use light and dark purple shades.

• Chocolate Purple: Replace ¼ cup flour with cocoa powder.

Nutritional Information*

Okay friends, let’s keep it real. This is a celebration cake, meant to be enjoyed with joy and maybe a glass of cold milk. Here’s a rough breakdown per slice (based on 12 servings), so you can savor it mindfully.

• Calories: ~510
• Total Fat: 26g
• Saturated Fat: 16g
• Carbohydrates: 64g
• Sugar: 51g
• Protein: 4g

*This is an estimate generated using a standard nutrition calculator. Values can vary based on specific ingredient brands, precise measurements, and any substitutions you make.

Final Slice of Thought

And there you have it, my friends—your guide to creating a Purple Birthday Cake that’s full of heart, flavor, and pure festive spirit. Remember, baking this cake isn’t about achieving some unattainable magazine perfection. It’s about the flour on your counter, the smell of vanilla in your kitchen, and the proud smile when you present something made with your own two hands. If it’s lopsided, call it rustic. If the purple is a little wild, call it avant-garde. The love is the main ingredient. Thank you so much for baking with me today. I hope this cake brings as much happiness to your table as it has to mine over the years. Now go forth, bake, and celebrate! Don’t forget to tag @Feastical if you share your creation—I love seeing your kitchen wins.

Until next time, keep it flavorful,
Beau