Step 1

Preheat oven to 350 degrees. Prepare two 6-inch cake pans. When finished, cakes will be cut horizontally making 4 layers.

Step 2

In a large bowl, mix the milk, sour cream, egg whites, and extracts then set aside.

Step 3

Sift the flour, sugar, baking powder, and salt into the bowl of a stand mixer. Mix at a slow speed. Add roughly tablespoon-sized pieces of room temperature butter to the flour mixture and mix on medium-low for an additional 2 minutes. You should end up with a relatively fine meal.

Step 4

Drizzle about half of the milk mixture into the mixer, while running on low. Scrape the bowl down then mix in the rest of the milk mixture.

Step 5

Distribute the batter evenly between the two pans.

Step 6

Bake for 27-30 minutes at 350F or until a toothpick inserted comes out clean.

Step 7

Invert the cakes onto a wire rack to cool completely.

Step 8

Whisk the yolks and sugar in a heatproof bowl then place over a pot of simmering water making sure that the water does not touch the bowl.

Step 9

Whisk in the milk slowly.

Step 10

Whisk constantly until the combined ingredients have thicker consistency. The internal temperature of the mixture should register at 170 degrees when you finish.

Step 11

Remove bowl from saucepan. Set bowl in ice water. Whisk the mixture until it has cooled (around 1 minute).

Step 12

Place mascarpone cheese in a large bowl. Fold the mixture into the cheese, using a rubber spatula.

Step 13

Miix until it is ALMOST COMBINED completely. Word of caution: do not over mix or it can have a grainy consistency.

Step 14

Add egg whites, sugar and salt in a bowl.

Step 15

Give the mixture a brief whisk.

Step 16

Place the bowl over a pan of simmering water. Make sure the water does not touch the bowl.

Step 17

Whisk the egg whites occasionally while it warms up. When the mixture has warmed, whisk it constantly. You will heat the mixture until it reaches an internal temperature of 160 degrees.

Step 18

Transfer the bowl to a stand mixer with a paddle attachment.

Step 19

While the mixture is running on low, add tablespoon sized dollops of room temperature butter making sure to let the butter incorporate before you add the next piece. In a small bowl mix 1 tbsp Instant espresso and 3 tbsp of Brandy then mix into the buttercream.

Step 20

You can transfer it to a piping bag or to a ziplock bag to store in the freezer for later. (When you're ready to use it, take it out of the freezer, bring to room temperature, transfer to a bowl and beat it for about 10 second to bring back the consistency).

Step 21

Mix the coffee, brandy, and liqueur. Set to the side.

Step 22

Cut cake layers in half

Step 23

Transfer cooled, mascarpone custard to a piping bag.

Step 24

Place first layer — cut side up — on a cake stand. Drizzle the coffee mixture on top (about 1/3 cup per layer).

Step 25

Pipe the mascarpone filling on top and dust with cocoa powder.

Step 26

Place next layer on top. Repeat until all layers have been added.

Step 27

Cover the cake in the Swiss Meringue and smooth. You can scrape the side for a “naked” look but that buttercream is so delicious you'll probably want a nice thick layer!

Step 28

Dust top with cocoa powder. Use the end of a spoon to remove to remove a ring of cocoa powder from the edge of the cake’s top (this will allow your dollops to adhere).

Step 29

Pipe dollops of Swiss Buttercream in a ring formation around the top, using an 869 Tip. Any Star tip will do though.