Preheat your oven to 500 degrees.
Using your fingers, work the shortening in with the flour in a large bowl until the flour appears crumbly, about the size of little peas.
Stir in the buttermilk, mashed sweet potatoes, and cinnamon with a wooden spoon.
Lightly dust your countertop with a little flour. Now, here is when the pizza cutter comes in! Pat the dough down into a neat rectangle – no need to do any kneading. Using a pizza cutter, slice the biscuits into 8 or 10 squares. Place the biscuits into a greased cast iron pan or if you don’t have one, a round cake pan or casserole dish will do, with the sides of the biscuits just touching.
Melt 3 tablespoons of butter and pour that on top of the biscuits. Bake for about 12-15 minutes, until lightly browned.
Melt a couple more tablespoons of butter and brush that on top of the freshly baked biscuits.
