Brown the Butter: Melt unsalted butter in a saucepan over medium heat, stirring until it turns a deep golden brown (5–8 minutes).

Mix Wet Ingredients: Combine cooled brown butter, brown sugar, maple syrup, pumpkin puree, and egg in a bowl; whisk until smooth.

Combine Dry Ingredients: In another bowl, whisk together flour, baking powder, baking soda, cinnamon, and pumpkin spice until combined.

Combine Mixtures: Gradually add dry ingredients to wet mixture, folding gently until just combined, avoiding overmixing.

Scoop and Bake: Preheat oven to 350°F (175°C). Use a cookie scoop to drop dough on prepared baking sheets, spacing 2 inches apart. Bake for 10–12 minutes.

Decorate: Let cookies cool on sheet for 5 minutes, then transfer to wire racks. Melt white chocolate and decorate cookies with ghost designs using a piping bag.