Turbinado sugar for topping (optional)
1/2 cup semisweet chocolate chips
1 tsp. vanilla extract
2 plain yogurt or sour cream
2 large eggs
1 1/2 cups mashed bananas (about 3 bananas)
1/4 cup butter, softened
1/2 cup packed brown sugar
1/2 cup granulated sugar
1 tsp. ground cinnamon
1/2 tsp. salt
3/4 tsp. baking soda
2/3 cup whole wheat flour
1 1/3 cups all-purpose flour