Instructions:  

1. Butter a 12” cast iron skillet and set aside.  
2. Whisk together pumpkin and ⅓ cup buttermilk in a small bowl. Set aside.  
3. Whisk together flour, baking powder, sage, sugar and salt in a large bowl. Grate butter into the flour mixture. Use two forks or a pastry blender to work in the butter until the mixture resembles coarse crumbs. Stir in the pumpkin mixture until just combined. Dough will be thick and crumbly.  
4. Dump the dough onto a lightly floured surface and knead a few times. Pat the dough into a loosely shaped rectangle that is about 1” thick. Fold the dough into thirds like a business letter. Reshape the dough into another 1” thick rectangle and repeat folding into thirds. Repeat the folding process one more time and then gently pat dough into an 8” circle about 1” thick.  
5. Use a 2 ½” biscuit cutter to cut as many biscuits out of the round of dough as possible and place in the prepared pan. Biscuits should be nearly but not quite touching. (This helps them rise up instead of out.) Reshape dough and repeat until you’ve cut and shaped all of the biscuit dough. Place the skillet in the refrigerator for 15 minutes.  
6. Preheat the oven to 425°F.  
7. Before baking, brush the tops of the biscuits with the remaining tablespoon of buttermilk, being careful not to let the liquid run down the sides of the biscuits. This helps them fully rise. Sprinkle with sea salt, if desired, and bake for 13-16 minutes or until lightly browned. Serve immediately.