1. Preheat oven to 350°F (175°C) and line a 9×13-inch baking pan with parchment paper.

2. In a light-colored saucepan, melt butter over medium heat, swirling until it foams and turns golden brown, then remove from heat and let cool for 5 minutes.

3. In a large bowl, whisk together cooled brown butter, brown sugar, granulated sugar, egg yolk, vanilla, and pumpkin purée until smooth.

4. In a separate bowl, whisk flour, baking powder, baking soda, salt, cinnamon, nutmeg, cloves, and ginger.

5. Fold dry ingredients into wet ingredients until just combined, taking care not to overmix.

6. Spread batter evenly in prepared pan using a rubber spatula.

7. Mix 3 tablespoons sugar and 1 teaspoon cinnamon, then sprinkle evenly over batter.

8. Bake for 28–32 minutes, or until edges are golden and a toothpick inserted near the center comes out with a few moist crumbs.

9. Cool in pan for 30–40 minutes, then lift out using parchment overhang and transfer to a cutting board.

10. Use a sharp knife to cut into 12 bars, wiping knife clean between cuts.

11. Optional: drizzle with maple glaze or vanilla icing and sprinkle chopped nuts before serving.