Preheat oven to 425˚F. Line a baking sheet with a silicone mat or parchment paper.

Add flour, brown sugar, baking powder, salt, black pepper, garlic powder, baking soda, and sage to a large bowl. Stir to combine.

Cut in 1/2 cup butter using two knives, a pastry cutter, or your hands until mixture resembles coarse crumbs. Stir in pumpkin and buttermilk, until just moistened.

Turn dough out onto a lightly floured surface. Knead the dough 8 to 10 times. Roll out until it's 1-inch thick. Cut into circles that are 2 to 2 1/2-inches in diameters.

Place biscuits 1 inch apart on the prepared baking sheet.

Bake for 18 to 22 minutes, until golden brown. Melt remaining butter and brush over biscuits. Serve warm.