For the Cake: 

1. Preheat the oven to 350°F. Prepare three 8-inch round baking pans, line the bottom with parchment paper and grease the sides. Prepare your bake even stripes if desired.
2. In a large mixing bowl, combine the sugar, vegetable oil, eggs and vanilla extract. Beat on medium speed until the eggs and oil are well incorporated and the batter is lighter in color. Next mix in the sour cream and beat until well combined.
3. In a separate bowl, sift together the dry ingredients. Then add half the dry ingredients followed by half of the coffee and mix just until the flour starts to incorporate. Then add the remaining dry ingredients and coffee. Beat until all of the ingredients are well combined. Use a spatula to scrape down the sides of the bowl and stir the batter from the bottom to the top to ensure it’s well mixed.
4. Divide the batter evenly between the three pans, about 1 2/3 cups of batter per pan. Bake at 350°F for 20-24 minutes. Rotate your pans in the oven halfway through baking.
5. Test the cake for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, your cake is done. Remove from the oven and allow to cool completely.

For the Frosting:

1. Wipe down the inside of your stainless-steel bowl with vinegar to remove any grease. Combine sugar and egg whites in the bowl with the candy thermometer attached.
2. Set the bowl over top of a pot with 1 ¼ cups water covering the bottom. Place over medium heat.
3. Stir constantly with a whisk until the mixture reaches 140°-160°  The sugar should be dissolved in the egg whites. You can test this by placing a drop on your fingertips and rubbing them together. The mixture should be completely smooth.
4. In a microwave-safe bowl, microwave the chocolate 50% power in 30-second increments, stirring each time until the chocolate is melted and smooth. Set aside to cool.
5. Immediately place the mixing bowl on your stand. Using the wire whisk attachment, beat the egg whites on low for 2 minutes then increase to medium-high.
6. Beat for another 5 minutes. At this point, your frosting should have turned white and the body of the meringue starts to form. Increase the mixing speed to high. It will start to look glossy as the peaks begin to form. Beat for another 5-8 minutes until the bottom of your bowl is cool to the touch and your meringue has stiff peaks.
7. Turn your mixer down to medium-low. Slowly add your butter, 1 tbsp at a time. As you add more butter, the frosting might appear to have curdled and lost its body, but that’s ok. Scrape down the sides of the bowl.
8. Switch to the paddle attachment, add the vanilla extract and continue beating on medium-high speed until your frosting starts to form. Slowly drizzle in the chocolate and continue beating until stiff peaks form about 3-5 minutes.

Assembly:

1. Level off your cakes by removing any domes. Place a dollop of frosting on your cake board and place the bottom layer of cake over that.
2. Pipe the first layer of frosting, pipe in circles filling working outside edge to the middle. Spread evenly with an offset spatula. Sprinkle each layer with ½ cup chopped peppermint bark. Add the second layer of cake and add the remaining frosting. Place the third layer of cake on top.
3. Use your offset spatula to press any excess frosting onto the edges of the cake. To finish, pipe the frosting along the outside edge of the cake using a large open round tip or a cake icer tip. Then use an offset spatula or icing smoother to create a smooth edge.
4. Gently press sprinkles into the bottom edge of the cake. To pipe, the rosettes on top, use a large piping bag, drizzle red food gel down one edge of the bag, and spread using a toothpick or knife. Fill the piping bag with the remaining frosting and pipe the border of the cake.