Step by step

1. Preheat the oven to 325 degrees F. Line the bottom of an ungreased, KitchenAid® Professional-Grade Nonstick Round Pan with a circle of parchment.

2. Sift the powdered sugar and cake flour together. Set aside.

3. Place the egg whites, cream of tartar, and salt together in the large bowl of the KitchenAid® Stand Mixer, and whip on medium-high speed (using the Wire Whip attachment) until foamy. Slowly add the granulated sugar, while continuing to whip. Add in the vanilla and almond extracts and whip until stiff peaks form.

4. In three additions, sprinkle the powdered sugar/cake flour mixture over the meringue, and gently fold until well incorporated. Transfer the mixture to the prepared KitchenAid® Professional-Grade Nonstick Round Pan, and bake for 45 minutes or until the cake is springy to the touch and a toothpick inserted in the center comes out clean, or with a few moist crumbs.

5. Run a thin knife around the inside perimeter of the pan, and turn the cake out onto a wire rack to cool.

6. For the devil’s food layers

7. Preheat the oven to 325 degrees F. Lightly mist a KitchenAid® Professional-Grade Nonstick Round Pan with nonstick spray, and line with a circle of parchment.

8. Place the sugar, flours, cocoa, baking powder, baking soda, and salt in the large bowl of the KitchenAid® Stand Mixer, and stir on low speed (using the Flat Beater attachment).

9. Add the softened butter, and stir on low speed until the mixture resembles moist sand.

10. Add the eggs, one at a time, scraping the bottom and sides of the bowl after each addition.

11. Add the Greek yogurt and vanilla, and mix on medium speed for about two minutes, to fully incorporate the ingredients and aerate and develop the structure of the cake.

12. Transfer the mixture to the prepared KitchenAid® Professional-Grade Nonstick Round Pan, and bake for 25 minutes, or until the cake is springy to the touch and a toothpick inserted in the center comes out clean, or with a few moist crumbs.

13. Turn the cake out onto a wire rack to cool.

14. For the salted caramel mousse

15. Place the water in a small bowl, and sprinkle the powdered gelatin over the surface. Set aside.

16. Whisk the egg yolks and sugar together in a large bowl until pale in color.

17. Place the milk in a small pot and heat over a low flame until just beginning to simmer. Slowly add the hot milk to the egg yolk mixture, a little at a time, whisking continuously, to temper the yolks and warm them gently.

18. Pour the mixture back into the pot and cook over low heat, whisking, until thickened. (The mixture should coat the back of a spoon.)

19. Whisk the softened gelatin into the egg/milk mixture. Cool to room temperature.

20. Place the cream in the small bowl of the KitchenAid® Stand Mixer. Using the Wire Whip attachment, whip on medium high speed until stiff peaks form.

21. Stir the whipped cream, egg mixture, and salted caramel together. Refrigerate.

22. For the salted caramel sauce

23. Place the cream, butter, and salt in a small pot, and heat until the butter is melted and the salt is completely dissolved. Remove from the heat and add the vanilla.

24. Place the sugar, corn syrup, and water in a medium pot, and place over high heat. Cook until amber in color (about 10 minutes), swirling occasionally.

25. Turn the heat to low, and pour in the cream mixture, whisking. The mixture will bubble up. Cook over low heat until smooth, then pour into a heat-safe vessel and allow to cool completely.

26. For the coffee buttercream

27. Place the egg whites and sugar in the large bowl of the KitchenAid® Stand Mixer. Place over a pot of simmering water. Cook, whisking occasionally, until the mixture no longer feels gritty when rubbed between the thumb and forefinger.

28. Remove the egg white mixture from the heat, and whip on medium-high speed (using the Wire Whip attachment) until there is no hint of warmth remaining, and the meringue holds stiff peaks.

29. Add the butter, a tablespoon at a time, while continuing to whip on medium-high speed.

30. Stir in the dissolved espresso powder until completely incorporated.

31. (If the buttercream seems runny, place the bowl in the refrigerator for 10-20 minutes, then whip again until fluffy and stiff.)

32. For the ganache

33. Chop the chocolate finely and place in a small bowl.

34. Heat the cream in a small pot until barely simmering.

35. Pour the hot cream over the chopped chocolate, and allow to stand for 5 minutes.

36. Whisk the chocolate and cream together until fully incorporated.

37. Whisk in the corn syrup and vanilla.

38. For the cake

39. Split the cakes horizontally into two layers each, using a serrated knife.

40. Lay one of the devil’s food layers on a serving plate. Layer a third of the salted caramel mousse on the cake, and spread in an even layer. Top with a layer of angel food cake.

41. Layer another third of the salted caramel mousse on the angel food cake, spreading in an even layer.

42. Repeat once again: devil’s food, mousse, angel food.

43. Wrap the cake tightly in plastic wrap and freeze for 2 hours minimum.

44. Ice the top and sides of the frozen cake with coffee buttercream. Drizzle with cooled ganache.

45. Optional: Pipe rosettes of whipped cream around the top edge, and garnish each with a chocolate covered espresso bean. Sprinkle the top of the cake with sea salt.

46. Refrigerate for a minimum of two hours before slicing.