Chocolate-chip-banana-bread-recipe-without-baking-powder, preheat oven to 350 degrees f. spray a 8"x5" (or similar size) loaf pan with baking spray (the kind with flour in it) and set aside. in a large bowl mash the bananas until completely smooth. stir in the melted butter until smooth. add the sugar, egg, vanilla, baking soda, salt and flour and stir until the batter is thick and combined.. 1 prepare pan and preheat oven: butter or spray with cooking spray the inside of a 5x9-inch loaf pan.preheat oven to 350°f (175°c) with a rack in the middle. 2 purée bananas: using a blender, food processor, or a fork, purée the peeled ripe bananas until smooth.you should have 1 1/2 to 1 3/4 cups of banana purée.