Robin Egg Snack Cake with Speckled Frosting

Close-up side view of a square slice of vanilla cake with speckled blue frosting.

5 from 4 votes

Robin Egg Snack Cake with Speckled Frosting

Robin egg-inspired blue speckled buttercream frosting makes this browned butter vanilla snack cake perfect for spring. And it tastes even better than it looks!

Prep Time45

Cook Time35

Total Time1 20

Course: Dessert

Cuisine: American

Servings:

Calories: 436kcal

Author: Allison Ferraro

Equipment

8x8 metal pan
Stand mixer or electric hand mixer
Stiff-bristled paint brush (new/clean)

Ingredients

Browned Butter Vanilla Cake:

1 ¼ cups cake flour
1 teaspoon baking powder
¼ teaspoon baking soda
½ teaspoon salt
6 Tablespoons unsalted butter, browned and at room temperature (see note at end of recipe)
⅞ cup granulated sugar
3 egg whites, room temperature
¼ cup sour cream, room temperature
1 ½ teaspoon vanilla extract
5 ounces whole milk, room temperature

Buttercream Frosting:

½ cup unsalted butter, room temperature
1 teaspoon vanilla extract
1 pinch fine sea salt
2 cups confectioners' sugar
1 Tablespoon whole milk
1 drop light blue gel food coloring

Chocolate Speckles:

¾ teaspoon unsweetened cocoa powder
1 ¼ teaspoons vanilla extract

US Customary - Metric

Instructions

Preheat the oven to 350°F. Line an 8 x 8 inch baking pan with parchment paper and set aside.

Make the cake.

In a small bowl, whisk together the cake flour, baking powder, baking soda, and salt. Set aside.
Add the butter to the bowl of a stand mixer (or a large bowl using an electric hand mixer) and beat the butter on high speed for about one minute, until smooth and creamy. Add the sugar and beat on high speed until creamed together, about 3-5 minutes.
Add the egg whites and beat on high speed until combined and fluffy, about 2 minutes.
Add the sour cream and vanilla extract and beat until combined. Scrape the sides of the bowl as needed while mixing.
With the mixer on low speed, add the dry ingredients and stir until just incorporated.
Keeping the mixer running on low speed, slowly add the milk and stir just until combined.
Pour the batter into the prepared cake pan. Bake for 35 minutes, until the top of the cake is golden and a toothpick inserted in the center of the cake comes out clean. Allow the cake to cool completely in the pan on a wire rack.

Make the frosting.

In the bowl of a stand mixer or a large bowl using an electric hand mixer, beat butter until smooth. Add vanilla and salt and mix well. Add sugar slowly – one cup at a time – beating well on medium speed and scraping the bowl often. When all sugar is added the frosting will be dry. Then add milk and beat at high speed until the frosting is light and fluffy.
Add the food coloring, starting with just one small drop, and beat until well combined. You can add more food coloring if necessary until the desired shade of blue is reached.

Decorate the cake.

Carefully lift the edges of the parchment paper to remove the cake from the pan. Spread the frosting generously onto the top of the cake.
In a small bowl, combine the cocoa powder and vanilla extract for the chocolate speckles and whisk until smooth.
Dip the bristles of a new or clean, stiff-bristled paint brush into the chocolate mixture. Holding the paint brush over the frosted cake, use your finger to gently pull back the bristles (away from the cake) and then release them (towards the cake) to flick the chocolate speckles onto the frosting.
Slice the cake into 9 squares and serve.

Notes

Storage: Store leftover cake in an airtight container at room temperature for up to 3 days.

Freezing: This cake can also be frozen, ideally before it's frosted. Wrap the completely cooled, unfrosted cake in a layer of plastic wrap followed by a layer of aluminum foil. Store in the freezer for up to one month. Thaw at room temperature before frosting and serving.

Browned Butter: Using browned butter (instead of regular, unsalted butter) is optional, but I love using browned butter because of the toasted, nutty flavor it adds to the cake. If you are using browned butter, you’ll need it to be room temperature. You can speed up the process of cooling the browned butter to room temperature by chilling it in the fridge for about an hour. You can also brown the butter up to 3 days in advance and refrigerate it, then let it come to room temperature normally before baking.

Be careful not to overmix the cake batter.

I used 1 drop of Americolor gel food coloring in the color sky blue to dye the frosting.

Nutrition