1 3/4 cups all-purpose flour (spooned and leveled)
2 tablespoons sugar
2 teaspoons baking powder
1 teaspoon baking soda
1/2 teaspoon coarse salt
1/4 cup (1/2 stick) unsalted butter, melted, plus more for brushing waffle iron
6 tablespoons creamy peanut butter
2 cups buttermilk
2 large eggs
3 bananas, sliced, for serving
3/4 cup pure maple syrup, for serving
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.
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.
Waffles can be frozen in zip-top bags, up to one month; reheat in the toaster or a 325-degree oven.