• Oil the bunt pans well and bake the chocolate cakes for about 20 minutes. Let them completely cool.
• Cut off the tops for a straight edge (tops while they are in the pan… so bottoms, really). This will make them all even when inverted together.
• Invert the cooled bunt apple cakes on top of each other, and secure with one or two toothpicks to hold securely in place.

Red Buttercream Frosting

• In a blender or food processor, pulse the sugar until powdery. Transfer the sugar to a medium heatproof bowl and whisk in egg whites and salt. Place the bowl over a saucepan of simmering water and whisk mixture gently until sugar is completely dissolved.
• Transfer the warm egg-white mixture to the bowl of a standing mixer fitted with a whisk attachment. Add the vanilla and beat beat at medium-high speed until stiff and glossy, about 8 minutes.
• Beat in the butter a few tablespoons at a time. Make sure pieces are fully incorporated before adding more. The buttercream should be light and fluffy. If it appears runny, place bowl in freezer for 5 to 10 minutes. Resume mixing.
• Mix in the red food coloring to dye the frosting red. Remove bowl from mixer and beat mixture with wooden spoon to remove any air bubbles.
• Frost the stacked bunt cakes with the homemade red frosting to look like an apple.