Chocolate Cake with Seven-Minute Frosting

Happy Birthday to my little man! I can't believe he is TWO!!!
Chocolate Cake with Seven-Minute Frosting

For Cake (makes 2 9-inch rounds):
Unsalted butter, for pans
1 1/2 cups unsweetened cocoa powder, plus more for pans
3 cups all-purpose flour
3 cups sugar
1 Tablespoon baking soda
1 1/2 teaspoons baking powder
1 1/2 teaspoons salt
3 large eggs
1 1/2 cups buttermilk
3/4 cup vegetable oil
1 1/2 teaspoons pure vanilla extract

1. Preheat oven to 350 degrees. Butter 2 round cake pans, and line bottoms with parchment; butter parchment, and dust with cocoa.
2. In the bowl of an electric mixer fitted with the paddle attachment, sift cocoa, flour, sugar, baking soda, baking powder, and salt. With the mixer on low, stir in eggs, 1 1/2 cups warm water, buttermilk, vegetable oil, and vanilla until smooth, about 3 minutes.
3. Divide batter among prepared pans. Bake, rotating once, until toothpick inserted in center comes out clean, 45-60 minutes.
4. Let cakes cool in pans on a wire rack for 20 minutes, then remove from pans and cool completely, right side up on rack.

For Frosting (for a double batch):
1 1/2 cup plus 4 tablespoons sugar
2 Tablespoon light corn syrup
6 large egg whites, room temperature

1. In a medium saucepan, combine 1 1/2 cup sugar, corn syrup, and 4 tablespoons water. Heat over medium heat, stirring occasionally, until sugar has dissolved. Raise heat to bring to a boil. Do not stir anymore. Boil about 5 minutes.
2. Meanwhile, in the bowl of an electric mixer fitted with the whisk attachment, whisk egg whites on medium speed until soft peaks form, about 2 1/2 minutes. Gradually add remaining 4 tablespoons sugar. Remove the syrup from the heat. Pour the syrup in a steady stream down the side of the bowl (to avoid splattering) containing the egg-white mixture, with the mixer on medium-low speed.
3. Beat frosting on medium speed until cool, 5-10 minutes. The frosting should be thick and shiny.

*I used blue food coloring to turn the frosting a light blue.

Source: adapted from Martha Stewart-One Bowl Chocolate Cake & Seven-Minute Frosting