Deep Dark Chocolate Sour Cream Zucchini Cake

INGREDIENTS

1/2 cup

butter, at room temperature

1/4 cup

canola or other mild vegetable oil

1 3/4 cups

sugar

large eggs

1 tsp

vanilla

2 1/4 cups

all purpose flour

3/4 cup

cocoa

1 tsp

baking powder

1 tsp

baking soda

1/2 tsp

salt

1 cup

sour cream or plain yogurt

2 cups

grated unpeeled zucchini (about 2 smallish, or 1 large)

3/4 cup

chopped walnuts or chocolate chips, or both (optional)