Poppy’s Homemade Vanilla Birthday Cake

I usually would buy birthday cakes for the kids, but last year at Poppy’s 4th birthday I made her this berry one and it turned out so great! The three layer was easier to do than I thought. Now it’s been fun to think of what kind of cake they want and how I can make it. I’m also able to use better ingredients this way too along with homemade frosting. I made this no-bake watermelon “cake” last year to display the fruit too, and it was a hit!

For Poppy’s mermaid cake I let her pick everything out ahead of time so we could pack it for our trip. She loved the mermaid figurine with the bubbles as well as this number 5 mermaid candle.

I asked her what kind she liked and she said vanilla with white frosting, so that was the plan. This one came out so spongy and moist, and she said it’s her favorite cake! I only put a thin layer of frosting between the layers, but depending on how much frosting you want, you could make the layers thicker. We put the leftovers in the fridge, and eating it cold the next day was also so delicious. I didn’t get a good picture of the inside of the cake until the next day when the kids were already digging into the frosting on the top (they LOVED the frosting), the sprinkles also made it look so festive and these ones are dye-free:

Elliott and Poppy were talking together about what cake he should choose for his birthday in November, it was really sweet! Last year I made him this checkered flag cake for a race car theme, which came out so adorable and I highly recommend it.

The recipe below includes how to make the frosting as well as what to do if you want to make cupcakes instead of the cake. Here’s the supplies I used for Poppy’s mermaid theme: balloons, mermaid streamers, iridescent steamers, mermaid cupcake liners.

Tools & Supplies

For Cupcakes

Prep Time: 25 min Bake Time: 30–40 min Total Time: ~1 hr 30 min (plus cooling) Serves: 12–16

Before You Start

1. Bring the butter, eggs, Greek yogurt, and buttermilk to room temperature before you begin. This helps the batter mix evenly and gives the cake a softer, lighter texture.

2. Preheat the oven to 350°F. Grease three 8-inch round cake pans with butter and line the bottoms with parchment paper, or I used an olive oil spray and sprayed down the parchment paper rounds after placing them inside.

3. Make sure the cake layers are completely cool before frosting. Even slightly warm cake can melt the buttercream.

For the Vanilla Cake

• 3¼ cups all-purpose flour

• ½ cup cornstarch

• 1 teaspoon baking soda

• 1 teaspoon baking powder

• ¾ teaspoon kosher salt

• 3 sticks (1½ cups) salted butter, softened

• 2 cups granulated sugar

• 3 whole eggs + 3 egg yolks, room temperature

• ¼ cup Greek yogurt, room temperature

• 1½ cups buttermilk, room temperature

• 1 tablespoon pure vanilla extract

For the Vanilla Buttercream

• 3 sticks (1½ cups) salted butter, softened

• 4½ cups powdered sugar

• 1 tablespoon pure vanilla extract

• Milk, 1 teaspoon at a time as needed

1. Preheat the oven to 350°F. Grease three 8-inch round cake pans and line the bottoms with parchment paper.

2. In a medium bowl, sift together the flour, cornstarch, baking soda, baking powder, and salt. Set aside.

3. In a large mixing bowl or stand mixer, beat the softened butter and sugar on medium-high speed for 3–4 minutes, until very pale, light, and fluffy.

4. Add the whole eggs one at a time, beating well after each addition. Add the egg yolks one at a time, then mix in the Greek yogurt and vanilla until combined.

5. Turn the mixer to low. Add the dry ingredients and buttermilk in alternating additions: flour, buttermilk, flour, buttermilk, flour. Mix only until the final streaks of flour disappear. Do not overmix.

6. Divide the batter evenly between the three prepared pans. Place the pans in the oven with at least 1 inch of space between them.

7. Bake for 30–40 minutes, until the tops spring back when lightly pressed, the edges begin to pull away from the pans, and a toothpick inserted into the center comes out with a few dry crumbs.

8. Let the cakes cool in their pans for 10 minutes. Turn them out onto cooling racks, remove the parchment, and allow them to cool completely before frosting.

1. Add the softened butter to a stand mixer and whip on medium-high speed for a full 5 minutes, until very pale and fluffy. Don’t rush this step. Whipping the butter thoroughly is what helps keep the frosting light instead of greasy.

2. Turn the mixer to low and add the powdered sugar 1½ cups at a time, scraping down the bowl between each addition.

3. Add the vanilla, then beat on medium-high speed for another 3 minutes until light and fluffy.

4. If needed, add milk 1 teaspoon at a time until the buttercream is soft and easy to spread.

1. Once the cake layers are completely cool, use a serrated knife to level the tops if they have domed.

2. Put a little buttercream frosting in the middle of the cake stand to help the cake avoid slipping. Place the first cake layer on your serving plate or cake stand and spread a thin, even layer of buttercream over the top. Repeat with the second layer, then add the final cake layer.

3. Spread a thin crumb coat of buttercream over the entire cake. Refrigerate for 15 minutes to set the crumb coat.

4. Cover the cake with the remaining buttercream and smooth the top and sides with an offset spatula.

5. If your kitchen is warm, refrigerate the finished cake and remove it about 1 hour before serving.

Use the same batter without making any changes. Line cupcake pans with liners and fill each about ⅔ full.

Bake at 350°F for 18–22 minutes, until the tops spring back and a toothpick inserted into the center comes out with a few dry crumbs.

The full recipe makes approximately 30 cupcakes.

For a half batch, halve all of the ingredients and use 2 whole eggs + 2 egg yolks. This will make approximately 15 cupcakes.