1. Preheat oven to 350°F and prepare a 9×11 rectangle cake pan. Grease pan with butter, making sure you are getting into the corners and edges. Line with parchment paper and press to the edges (this will help you remove the cake after it is cooked). Set the pan aside while you make your batter. 
2. In a large mixing bowl, add flour, baking soda, salt and cocoa powder. Whisk together until blended and set aside. 
3. In a stand mixer, beat sugar and butter. Add in eggs and sour cream, coffee and beat until just combined.
4. Add in your dry mixture to the wet in thirds and mix until just combined. Stir in your chocolate chips. 
5. Pour batter into greased bake pan and cook in oven for 20-25 minutes. Make icing while cake is cooking.
6. Once cake is done, remove from oven and cool completely before adding your icing. After it is cooled and iced, top with choice of chocolate sprinkles or chocolate shavings, slice and enjoy!

Homemade Chocolate Icing

1. While your cake is cooking, make your icing. Using your electric mixer, beat butter until smooth. Add in milk, cocoa powder, powdered sugar, vanilla and blend until creamy. Set aside until cake is cooked.