Ingredients

• vegetable-oil cooking spray
• 1 cup all-purpose flour
• 1 teaspoon baking powder
• 1/4 teaspoon baking soda
• 1/2 teaspoon salt
• 3/4 stick (6 tablespoons) unsalted butter
• 1 cup well-shaken buttermilk
• 1 large egg
• 4 thin slices prosciutto
• sour cream
• pure maple syrup

Instructions

1. Preheat oven to 250°F. Spray an unheated well-seasoned or nonstick Belgian waffle iron with cooking spray and preheat iron.
2. Into a large bowl sift together flour, baking powder, baking soda, and salt. Melt 5 tablespoons butter and in a small bowl whisk together with buttermilk and egg until combined. Stir butter mixture into flour mixture until smooth (batter will be thick).
3. Spoon batter into waffle iron, using 1 cup batter for two 4-inch-square Belgian waffles (see note, above) and spreading evenly, and cook according to manufacturer's instructions. Transfer waffles to a baking sheet and keep warm, uncovered, in middle of oven. Make more waffles in same manner (do not respray iron).
4. In a large heavy skillet heat remaining tablespoon butter over moderate heat until foam subsides and cook prosciutto slices until crisp and golden, about 1 minute on each side.
5. Serve waffles with prosciutto, sour cream, and maple syrup.