Preheat your oven to 350°F (175°C). Gather ingredients and baking equipment, including a mixing bowl, whisk, and a 9x9 inch baking pan.

Whisk together 1 ½ cups of all-purpose flour, 1 teaspoon baking powder, 1 teaspoon ground cinnamon, and ½ teaspoon ground nutmeg in a medium bowl.

Combine ½ cup melted butter with 1 cup packed brown sugar in a large mixing bowl until smooth. Then add 1 cup pumpkin puree, 2 large eggs, and 1 teaspoon vanilla extract. Blend until smooth.

Gradually add the dry mixture to the wet ingredients, stirring gently until just combined.

Reserve about a cup of the batter, then mix it with additional cinnamon and nutmeg for a flavorful swirl. Fold back into the main batter.

Pour the blondie batter into the prepared pan, spreading it evenly. Sprinkle a mixture of 2 tablespoons granulated sugar and 1 teaspoon cinnamon over the top.

Bake in the preheated oven for 25-30 minutes until a toothpick inserted in the center comes out clean or with a few moist crumbs.

Allow the blondies to cool in the pan for about 10-15 minutes, then transfer to a wire rack to cool completely before slicing.