Pumpkin Cookies with Spiced Plum Jam

Preheat the oven to 350°F (175°C). In a large bowl, cream together the butter and brown sugar. Beat in the egg and vanilla extract. In a separate bowl, whisk together the flour, baking powder, cinnamon, nutmeg, and salt. Gradually add the dry ingredients to the wet ingredients, mixing well. Fold in the pumpkin puree. Drop spoonfuls of the dough onto a baking sheet lined with parchment paper. Bake for 10-12 minutes, or until the edges are golden brown. Allow the cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely. Once cooled, spread spiced plum jam on the bottom of one cookie and sandwich it with another cookie. Dust with powdered sugar before serving.