8 tablespoons melted unsalted butter, at room temperature
1 cup sugar
1 extra large egg
1 teaspoon vanilla extract
About 4 tablespoons peanut butter
In a medium bowl, whisk together flour, cocoa powder, baking powder, baking soda, and salt; set aside. In a large bowl, cream together butter and sugar with an electric beater until light and fluffy, about 3 minutes. Beat in egg and vanilla extract. Add flour mixture and beat until just combined. Dough should come together, if too crumbly, add 1 teaspoon water. Form dough into a ball, cover with plastic wrap and chill in refrigerator for one hour.
Adjust oven rack to upper and lower middle positions and preheat oven to 350°F. Line two baking sheets with parchment paper. Divide dough in half and roll one half out onto a lightly floured surface to a thickness of approximately 1/8th- inch. Cut out 12 pumpkins using a pumpkin-shaped cookie cutter and transfer to a prepared baking sheet. Repeat with remaining dough. Using a pairing knife, cut jack-o-lantern faces into 1/2 of the cookies. Bake cookies until just dry on top, about 10 minutes. Let cool for 5 minutes then transfer to a wire rack to finish cooling. When completely cooled, spread top of faceless cookies with about 1 teaspoon of peanut butter (more or less depending on how much you like peanut butter). Top with a face cookie to complete sandwiches.