1 tablespoon baking powder
1/2 teaspoon ground cinnamon
1/4 teaspoon salt
6 tablespoons unsalted butter, melted
2 large eggs, room temperature
2 tablespoons packed brown sugar
1 3/4 cup buttermilk
1 teaspoon pure vanilla extract
Preheat the waffle maker on medium-high heat. Preheat the oven to 200°F. Place a wire rack on a baking sheet; set aside.
In a large bowl, whisk together the flour, baking powder, cinnamon, and salt. Set aside.
In another large bowl, whisk the melted butter, eggs, and brown sugar together. Whisk in the buttermilk and vanilla until combined. Pour the wet ingredients into the dry ingredients and then whisk gently until combined. Do not over-mix; some small lumps are okay.
Grease the preheated waffle maker with non-stick cooking spray. Pour the batter into the waffle maker and close the lid. Cook the waffles until crisp, about 4–5 minutes.
Transfer the cooked waffles to the wire rack and keep them warm in the preheated oven as you cook the remaining batter. Repeat to cook the remaining batter.
Serve the waffles immediately.