3 C. flour

3 C. sugar

3 cubes butter

6 Tbsp. cocoa

1/2 C. water

3/4 C. sour cream

1 1/2 tsp. baking soda

3 eggs. beaten

4 tsp. vanilla

3/4 tsp. salt

Mix flour and sugar. Melt butter cocoa, and water in a pan; pour into the flour and sugar. Mix sour cream with baking soda in small bowl; wait a minute or two, then add to the flour mixture along with the eggs, vanilla, and salt. Pour into a 9 X 13 inch pan and a 8 X 8 inch pan. Bake at 325 degrees for 45 minutes. Let cake cool completely. 

Chocolate Buttercream Frosting:

1 C. butter softened

3-4 C. powdered sugar

1/2 C. cocoa powder

1-2 Tbsp. milk or half & half

1 tsp. vanilla extract

In large mixing bowl, beat butter until fluffy. Add three cups powdered sugar, cocoa powder, 1 Tbsp. milk, and vanilla extract. Beat until combined and fluffy. Adjust with more sugar or more milk, depending on what consistency you're looking for. Frost cooled cake.