Best ever chocolate cake

I got this recipe on Pinterest.
(I changed the coffee to orange juice with 2 teaspoons of cocoa powder added)

BLACK MAGIC CAKE (BEST CHOCOLATE CAKE EVER!)

INGREDIENTS

- 1 3/4 c all purpose flour - 2 c sugar - 3/4 c cocoa powder - 2 tsp baking soda - 1 tsp baking powder - 1 tsp salt - 2 eggs - 1 c strong black coffee, cooled - 1 c buttermilk

- 1/2 c vegetable oil - 1 tsp real vanilla extract CHOCOLATE FROSTING - 1/2 c margarine, softened - 2 oz melted unsweetened chocolate, cooled - 3 c powdered sugar - 3 Tbsp milk - 2 tsp real vanilla extract

DIRECTIONS

1.   Combine flour, sugar, cocoa, baking soda, baking powder, and salt in a large mixing bowl or stand mixer.

2.   Add eggs, coffee, buttermilk, oil, and vanilla.

3.   Beat at medium speed for two minutes. Batter will be thin.

4.   Pour batter into a greased and floured 9x13 pan or two 9 inch cake pans.

5.   Bake at 350 degrees for 35-40 minutes for a 9x13, or 30-35 minutes for layer pans.

6.   Combine frosting ingredients and mix with a hand or stand mixer. Spread frosting on cooled cakes.