Chocolate zucchini cake

1 cup butter
1 ¼ cups sugar
2 large eggs, lightly beaten
½ cup sour cream
1 tsp pure vanilla extract
2 ½ cups flour
¼ cup cocoa powder
1 tsp cinnamon
1 tsp baking soda
½ tsp baking powder
2 cups grated zucchini
2/3 cups chocolate chips

In a large bowl, with an electric mixer on medium speed, cream together butter and sugar. Beat in eggs, sour cream and vanilla. In a separate bowl, whisk together flour, cocoa powder, cinnamon, baking soda and baking powder. Fold into butter mixture until smooth but not over mixed. Fold in zucchini and chocolate chips. Divide batter between two prepared loaf or cake pans and bake at 350 degrees for 45 minutes, or until a tester inserted into the centre comes out clean.