01 - Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.
02 - In a large mixing bowl, whisk together all-purpose flour, light brown sugar, baking powder, baking soda, salt, ground cinnamon, and ground nutmeg.
03 - Cut in the cold cubed butter using a pastry cutter or fork until the dough forms coarse crumbs.
04 - In a separate bowl, blend the pumpkin puree, buttermilk, and vanilla extract. Stir this mixture into the dry ingredients until just combined.
05 - On a lightly floured surface, gently pat the dough to about 1/2-inch thickness. Cut out 24 circles using a 2-inch round cutter.
06 - Place 12 dough circles on the prepared baking sheet. Top each with a marshmallow and insert a lollipop stick into the marshmallow so it reaches halfway up.
07 - Cover each marshmallow with a second dough circle, pressing edges gently to seal.
08 - Bake in the preheated oven for 16–18 minutes, or until pops are golden brown. Transfer to a wire rack to cool completely.
09 - Melt semi-sweet chocolate in a microwave-safe bowl or double boiler until smooth. Dip tops of each cooled pop in melted chocolate and immediately sprinkle with graham cracker crumbs. Allow to set on parchment paper.