Chocolate Banana Bread Squares

Preheat an oven to 350°F (175°C) and line a 9x9 square pan with parchment paper. A loaf pan can also be used. In a mixing bowl or stand mixer, mash the ripe bananas. Add the melted butter, egg, vanilla extract, and yogurt, and mix until combined. Add the brown sugar and granulated sugar and mix until combined. In a separate small mixing bowl, combine the flour, cocoa powder, salt, and baking soda. Add the dry ingredients to the wet ingredients and mix until just combined. Fold in 1 cup of the chocolate chips using a spatula. Pour the batter into the lined pan and top with the remaining 1/3 cup of chocolate chips. Bake for 45 minutes if using a square pan, or approximately 55 minutes if using a loaf pan. Cool for 30 minutes before cutting and serving.