4 oz. unsweetened chocolate (optional)
1/2 c. butter at room temperature
3 eggs (beaten)
2 c. sifted all-purpose unbleached flour
2 tsp. baking powder
1/2 c. vegetable oil
2 c. sugar
1 tbsp. vanilla extract
1/3 c. cocoa
2 tsp. baking soda
1/3 c. buttermilk or sour cream
1/2 c. chopped nuts
1 tsp. salt
3 c. coarsely grated zucchini or summer squash

Preheat oven to 350 degrees. Melt the chocolate and oil in a small saucepan over very low heat. Cream butter until light; add the sugar, eggs, and vanilla. Beat well. Add the melted chocolate and mix well.

Sift together the dry ingredients and stir them into the batter with the buttermilk. Mix the zucchini and nuts into the batter. Grease and flour 2 (9-inch) cake pans. Divide the batter between pans. Bake on the middle shelf of the oven for 40 minutes or until a toothpick comes out clean. Cool completely before frosting.