– 1 ⅔ cups 235g all-purpose flour – ½ cup 42g cocoa powder (I prefer this one) – 1 ½ teaspoon baking powder – ½ teaspoon baking soda – 1 teaspoon espresso powder – ½ teaspoon salt – 2 large very ripe bananas (about 1 cup/240ml mashed) – ⅓ cup 65g granulated sugar – ⅓ cup 70g packed light brown sugar – ¾ cup 175ml full fat sour cream – ¼ cup 60ml vegetable oil – 1 tsp 5ml pure vanilla extract – 2 large eggs at room temperature – 1 cup 6oz/170g dark chocolate chips