Preheat your oven to 350°F (175°C) and prepare three or four 8-inch round cake pans by lining the bottoms with parchment paper and greasing the sides.

In a mixing bowl, combine the all-purpose flour, granulated sugar, baking powder, and fine salt. Whisk together until well blended.

Add the unsalted butter to the dry mixture and beat on medium speed until the mixture is light and fluffy, about 3-4 minutes.

Next, add in the egg whites, sour cream, vegetable oil, almond extract, and vanilla extract. Mix on low speed until just incorporated.

Divide the batter equally among sequential bowls for coloring. Add red gel food coloring to one bowl and green to another.

Pour the colored batters into the prepared cake pans and bake for 33–36 minutes, or until a toothpick inserted in the center comes out clean.

Remove the cakes from the oven and allow them to cool in the pans for about 10 minutes before turning them out onto wire racks.

In a mixing bowl, beat the unsalted butter until light and fluffy, then gradually add powdered sugar, extracts, salt, and heavy whipping cream.

Apply a thin layer of buttercream to each cooled cake layer to seal in crumbs, then refrigerate for at least 30 minutes.

Using colored buttercream, pipe Santa’s suit in red and his belt in black along with any other festive details.

Finish by adding Santa's facial features using additional buttercream and candies for eyes, a nose, and rosy cheeks.

Let the decorated cake sit at room temperature for about 30 minutes before slicing.