Preheat oven to 350 degrees F (175 degrees C). Grease and flour one 9x13 inch cake pan.
In a large bowl cream together butter and sugar until light and fluffy.
Add eggs one at a time, beating after each addition.
In a separate bowl combine flour, baking powder, baking soda, salt, and cocoa powder. Add to creamed mixture alternately with buttermilk, mixing after each addition.
Stir in vanilla extract and chocolate chips.
Pour batter into prepared pan and bake for 35 minutes or until a toothpick inserted in the center comes out clean.
Cool in pan for 15 minutes, then turn out onto a wire rack to cool completely.
Interesting Facts
This recipe is a variation of the classic chocolate cake.
The addition of buttermilk makes the cake extra moist and flavorful.
The chocolate chips add a delicious texture to the cake.