Doberge Cake

Directions

For Cake:

1. Preheat oven to 375°F and grease a 9-inch cake pan using nonstick cooking spray.
2. Beat all the egg whites in a glass or metal bowl until foamy and continue to beat until stiff peaks form. Set aside.
3. In a separate bowl, sift together cake flour and baking powder.
4. In the bowl of an electric mixer, or in a large mixing bowl, beat ¾ cup butter, 2 cups sugar, and ½  teaspoon salt until texture is light and fluffy, and light in color.
5. One at a time, add the egg yolks, incorporating each before adding the next.
6. Alternate pouring in cake flour mixture and 1 cup of milk, mixing until just incorporated.
7. Stir in the lemon juice and vanilla extract.
8. Whisk beaten egg whites once or twice then, working with a whisk or rubber spatula, fold ⅓ of the egg white mixture into the cake batter to lighten it, then fold in the remaining egg whites, mixing until just combined.
9. Pour the batter into the cake pan, spreading evenly over bottom.
10. Bake 15–20 minutes, until golden-brown and just pulling away from sides of pan. Avoid overbaking.
11. Let the cake cool in the pan 5 minutes, then invert over a cooling rack and let cool completely.

For Custard:

12. In a saucepan, combine 1½ cups sugar, salt, flour, cornstarch, and baking cocoa.
13. In a separate bowl, whisk remaining ½ cup sugar with eggs.
14. Add milk to the saucepan and bring it to a boil over medium heat.
15. Remove from heat and gradually add the contents of the pan to the sugar and eggs, whisking constantly.
16. Add the chopped chocolate and stir until melted.
17. Return the custard to the saucepan and cook over medium heat, stirring constantly about 5 minutes or until mixture has thickened.
18. Remove from heat, and stir in the butter and vanilla extract.
19. Transfer the custard to a bowl and let cool completely.

For Buttercream Frosting:

20. Cream together the butter and powdered sugar in a bowl.
21. Stir in baking cocoa.
22. Add vanilla extract and continue to mix until frosting is smooth. Add hot water as needed to reach the desired consistency.

For Ganache:

23. Place the chocolate chips in a large mixing bowl.
24. Heat heavy cream in a saucepan until very hot but not yet boiling, and pour it over the chocolate chips.
25. Let rest for 3 minutes, then mix with a whisk, scraping the sides of the bowl, until smooth.
26. Stir in vanilla extract.
27. Let ganache cool to room temperature, then cover, and set aside. The texture should be spreadable and not too firm.

For Assembly:

28. Slice each cake layer in half horizontally with a long, serrated knife.
29. Cover a cake plate with parchment or foil and place a dab of buttercream frosting in the center.
30. Place one of the cake halves on top of the plate.
31. Spread a layer of custard filling over the cake, not spreading all the way to the edges of the circle.
32. Place another layer of cake over the custard, and spread it with custard.
33. Repeat layers of cake and custard, topping with the final cake layer.
34. Chill for 30 minutes.
35. Frost the top and sides of the cake with buttercream.
36. Chill for 30 minutes.
37. Spread the frosted cake with ganache.
38. Store refrigerated.