Chocolate cake

I always want to make the cakes for the kid's birthdays but I never actually serve them at a party. We have fun eating cake for days though!
I made two chocolate cakes this time then called and ordered the one for Justin's party. The cake on the left is the sheet cake and the cake on the right is the dark chocolate cake. Hunter's favorite was the sheet cake while Corrine's was the dark chocolate.
With a good chocolate icing they'd both be perfect for a birthday cake!

Sheet cake
Ingredients:
2 cups all-purpose flour
2 cups white sugar
1 teaspoon baking soda
2 eggs
1 teaspoon vanilla extract
1/2 cup buttermilk
1/2 cup butter
1/2 cup vegetable oil
1 cup water
1/2 cup unsweetened cocoa
powder
Directions

Preheat oven to 350 degrees F (175 degrees C). Grease and flour an 11x17 inch sheet cake pan.

In a large bowl, sift together the flour, sugar and baking soda. Stir in the eggs, vanilla and buttermilk. Set aside. In a saucepan combine butter, oil, cocoa and water. Bring to a boil and stir until smooth. Slowly blend into the flour mixture. Pour into prepared pan.

Bake in the preheated oven for 15 to 20 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool.

Dark chocolate cake
Ingredients
2 cups all-purpose flour
2 cups white sugar
3/4 cup unsweetened cocoa
2 teaspoons baking soda
1 teaspoon baking powder
1/2 teaspoon salt
2 eggs
1 cup cold brewed coffee
1 cup milk
1/2 cup vegetable oil
2 teaspoons vinegar
Directions
Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9x13 inch pan.
In a large bowl, combine the flour, sugar, cocoa, baking soda, baking powder and salt. Make a well in the center and pour in the eggs, coffee, milk, oil and vinegar. Mix until smooth, batter will be thin. Pour into prepared pan.
Bake in the preheated oven for 35 to 40 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool.