Use 11 x 16 inch jelly roll pan.

3/4 c. milk + 1 tbsp.
1 1/2 tsp. lemon juice
2 c. sugar
1 tsp. cinnamon
2 c. flour
1/2 tsp. salt
3 tsp. baking soda
3 qts. butter (1 1/2 c.)
8 tbsp. cocoa
1 c. water
2 eggs
1 box powdered sugar
1 tsp. vanilla

Preheat oven to 400 degrees. Spray pan with Pam. Combine 1/2 cup milk with lemon juice to sour the milk. Combine 2 quarters (1 cup) butter, 4 tablespoons cocoa, 1 cup water in saucepan and bring to a boil.

In mixing bowl, combine granulated sugar, cinnamon, flour, salt and 1 teaspoon baking soda - pour saucepan mixture into dry mixture and mix well. Add the eggs and 1 teaspoon baking soda to the sour milk and add to the mixing bowl and beat well.

Pour into pan and bake 20 minutes. While the cake is baking - start the frosting by combining 1 quarter (1/2 cup) butter, 4 tablespoons cocoa, 5 tablespoons milk in saucepan and bring to a boil. Remove from heat and add 1 box powdered sugar and 1 teaspoon vanilla and beat until smooth. Let the cake cool for a few minutes and then frost.