Preheat oven to 350F. Grease and flour three 8-inch round cake pans and set aside.

In a medium bowl, mix together the dry ingredients for the yellow cake - cake flour, granulated sugar, baking powder, and salt.

In a small bowl, mix together the egg, vanilla and two tablespoons of the buttermilk. Then, add the softened butter to the dry ingredients and mash it around until it is fully incorporated.

Pour the egg mixture into the dry ingredients and whisk until blended.

Add the remaining buttermilk and mix with a hand mixer, until smooth.

Now to make the chocolate batter, in a medium-sized bowl, mix together the dry ingredients for the chocolate cake - cake flour, granulated sugar, cocoa powder, baking soda, and salt.

Then, in a small bowl, whisk together the egg, vanilla, buttermilk.

Add the butter to the dry ingredients and mash it around until blended.

Then add the wet ingredients to the dry and stir together.

Pour in the cooled coffee and then blend with a hand mixer until smooth.Now you have a bowl of vanilla batter and a bowl of chocolate batter.

Divide the vanilla batter between each of the pans.

Then take the chocolate batter, and pour that on top of the vanilla.

Use a spoon to carefully spread the chocolate to the edges of the pan. Make sure you layer the vanilla first, because the batter is thicker than the chocolate batter.

Bake at 350F for 25 minutes, or until a toothpick inserted into the middle of the cake comes out clean.

Cool the cake for 20 minutes and then invert onto a drying rack to finish cooling.

Let cool completely.

To make the mocha filling, beat together the butter, instant coffee granules, powdered sugar, and 1 tbsp of heavy cream until well blended.

Gradually add more cream until you get it to a spreadable consistency.

Spread on top of two of the cakes once cooled.

Then, carefully stack the cakes.

To make the whipped cream, in the bowl of a stand mixer fitted with the whisk attachment, beat 1 cup of powdered sugar.

When soft peaks begin to form, add in the vanilla and powdered sugar.

Beat just until stiff peaks form. Do not over beat, as your whipped cream will curdle. Spread on the cake in a whimsical fashion with the back of a spoon.

Keep refrigerated until serving.