Banana Waffles

Ingredients

• 1 3/4 cups all-purpose flour
• 1 3/4 teaspoons baking powder
• 1/8 teaspoon fine salt
• 1/8 teaspoon ground nutmeg
• 1 1/2 cups milk, at room temperature
• 2 large eggs, at room temperature, separated
• 1/2 teaspoon vanilla extract
• 1/4 cup unsalted butter, melted, plus more for brushing the iron
• 1 large egg white, at room temperature
• 1/4 cup sugar
• 2 bananas, mashed
• Serving suggestions: Maple syrup, jam, fresh fruit, or yogurt