Mahogany Cake . Come See our Unique Cake Gifts! As it happens, Mahogany cake is also an awesome study in the subject of baking chemistry — and the alchemy of the ingredients. Granny's Mahogany Cake and Frosting Granny's Mahogany Cake and Frosting. Mahogany cakes are one of the first cakes to incorporate chocolate and coffee in the batter. It is delicious, all natural and has surprisingly mild but enticing flavors. The idea for red velvet cake might even have come from mahogany cake. You can cook Mahogany Cake using 11 ingredients and 9 steps. Here is how you cook that. Ingredients of Mahogany Cake It's 2 cups of flour. You need 1 tsp. of baking soda. It's 1 tsp. of salt. It's 1/2 cup of butter. You need 1 1/2 cups of sugar. You need 3 of eggs. Prepare 2 oz. of unsweetened chocolate. You need 1 cup of strong black coffee, divided. You need 1 tablespoon of vinegar. It's 1...