1. Heat waffle iron and preheat oven to 275 degrees; set a wire rack in a rimmed baking sheet and place in oven. In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt. In a blender, blend butter and peanut butter until smooth, 1 minute. Add buttermilk and eggs and blend until combined, 1 minute. Add buttermilk mixture to flour mixture and stir just until batter is combined.

2. Brush waffle iron with butter and pour in 1/2 to 3/4 cup batter, leaving a 1/2-inch border on all sides. Close iron and cook until waffles are golden brown, 2 to 4 minutes. Transfer waffles to rack in oven to keep warm; repeat with remaining batter. Serve with bananas and maple syrup.