White Chocolate Cake with White Chocolate Icing

1 . Stage

Preheat the oven to 300 degrees F (150 degrees C). Grease and flour three 8-inch round cake pans or line with parchment paper.

2 . Stage

Place chopped white chocolate in the top of a double boiler over simmering water. Stir frequently, scraping down the sides with a rubber spatula to avoid scorching, until chocolate is melted, about 5 minutes.

3 . Stage

Cream sugar and butter together using an electric mixer until fluffy. Add 4 egg yolks, 1 at a time, beating well after each addition. Mix in vanilla extract and melted chocolate.

4 . Stage

Combine flour, baking soda, and salt in another bowl. Blend into butter mixture, alternating with buttermilk, beating well after each addition.

5 . Stage

Beat egg whites in a separate bowl until stiff; fold into batter. Pour batter evenly into the prepared cake pans.

6 . Stage

Bake in the preheated oven until a toothpick inserted into the center of each layer comes out clean, 25 to 30 minutes. Remove from the oven and let cool completely, about 30 minutes.

7 . Stage

Combine melted white chocolate, confectioners' sugar, hot water, butter, egg yolks, vanilla extract, and salt in a mixing bowl; beat into a smooth icing using an electric mixer.

8 . Stage

Place 1 cake layer on a serving plate. Cover with some frosting and another cake layer. Repeat once more. Frost the top and sides of the cake with the remaining icing.