• Preheat oven to 350°F. Line baking sheets with parchment paper and set aside.
• In a medium bowl, combine the flour, baking soda, baking powder, cinnamon, nutmeg and salt. Set aside.
• In a separate large bowl, cream the butter and sugar until well blended. Add the pumpkin, egg and vanilla and mix until smooth. Gradually add the flour mixture.Drop by rounded tablespoonfuls onto the prepared baking sheets.
• Bake for 15-18 minutes or until the edges are firm. Allow to cool on the baking sheet for 2-3 minutes then remove to wire racks to cool completely.

While the cookies are cooling, prepare the frosting:

• Place 1 stick of butter in a small saucepan. Allow to melt over medium-low heat. Continue to cook, swirling on occasion to check the color, until the butter is browned. Remove from the heat and allow to cool completely. Beat the remaining half a stick of butter until creamy. Slowly beat in the browned butter until it looks well combined. Add the brown sugar, pumpkin, cinnamon, nutmeg - mix well. Slowly add the powdered sugar and mix well. If you prefer a thicker frosting, you can add more powdered sugar - if you need a thinner frosting, add a little milk.
• After the cookies have cooled completely, frost the cookies.
• Store cookies in an airtight container.