Tender dark chocolate cake layers filled with creamy milk chocolate buttercream.
Preheat oven to 350 °F. Spray three 6-inch round cake pans or two 8-inch round cake pans with non-stick spray, line the bottom of each pan with parchment paper and spray again. Set aside.
In the stand mixer bowl fitted with a paddle attachment, stir together the all-purpose flour, granulated sugar, dark cocoa powder, baking soda, and salt. Set aside.
Add the eggs and the vegetable oil on low until well incorporated.
Pour in the buttermilk and add brewed coffee. Mix on medium for 30 seconds. Scrape down the sides of the bowl.
Evenly distribute the cake batter among the three cake pans and bake for about 35-40 minutes or until a toothpick inserted into the center of each cake comes out clean or with just a few moist crumbs.
Remove cakes from oven and let cool in pans for 10 minutes before inverting onto cooling racks to cool completely — wrap cakes in plastic wrap and place in the freezer to chill for 30 minutes.
In the stand mixer bowl fitted with the paddle attachment, beat the butter until light and fluffy, about 2 minutes.
Turn the mixer to low and add vanilla and salt. Then gradually add the powdered sugar and cocoa powder, followed by the cream. Mix until combined. Mix until incorporated completely. Scrape down sides of the bowl.
Turn the mixer to medium-high and beat the frosting for about 5 minutes until light and fluffy. Add a tiny dot of green and yellow gel food color as needed. Then turn the mixer on low and mix for 2 minutes to push out any air bubbles.
In a medium bowl, microwave the dark coating chocolate in 30-second increments until it’s melted. Place melted chocolate into a piping bag.
On a baking sheet with a piece of parchment paper, pipe 2-3 pairs of antlers and insert a covered wire into each antler before it dries. If needed, add more chocolate on top to cover the wire.
Set aside to dry for 30 minutes.
On a silicone mat, roll the red fondant to 1/8 inch thick then use a sharp x-acto knife to cut out one long strip. Flip strip over and add a touch of water to the middle of the strip. Fold each end to meet in the center. Then pinch the center together and cut a thin strip to wrap around the center to create a bow.
Roll a piece of red fondant into a 1 ½- inch nose.
Roll out light brown fondant to 1/8 inch thick, cut out two oval ears. Then roll out light pink fondant for the inner ears. Attach with water and pinch the ends to create a crease in the ear. Insert a covered wire into each ear.
Next, roll black fondant into a 1/8 inch thick rope. Cut into two small pieces and form into whimsical eyes. Cut out two small pieces for eyelashes for the ends. Add white fondant highlights on the red nose and black eyes. Use water to attach the white fondant. Set aside to dry 1 hour.
Remove the cake layers from the freezer and unwrap the cake layers. Next, use a serrated knife to cut off the dome of the cakes to make the layers flat and even.
Add a small amount of buttercream onto the center of the cake board. Layer the chilled dark chocolate cake, cut side up onto the cake board.
Add a 2/3 cup of chocolate buttercream over the cake. Place another cake layer cut side down over the top. Repeat process for another layer. Crumb coat and freeze for 30 minutes.
Add a thick layer of buttercream all over the cake. Use an offset spatula to fill in any gaps with more buttercream. Then use a cake scraper to smooth out the sides of the cake. Use the offset spatula to make the top edges sharp and smooth.
Insert toothpick into red nose and insert nose into the side of the cake. Add the fondant eyes as well as antlers and ears.
Pipe the hair with small swirls of chocolate buttercream on top of the reindeer. Place the red bow in front of one antler.
Next, pipe holly leaves all over the bottom of the cake followed by piping red dots randomly in the leaves for a pop of color. Serve cake at room temperature.