Preheat oven to 425F. Set rack in upper third position. Prepare 9-inch round baking pan by brushing bottom with melted butter.
In a large bowl, add flour, sugar, and salt and stir to combine. Create a well in the center of the flour.
Using your hands, add cold shortening into the middle of the flour mixture and start mixing into the flour, keeping in larger pieces, about the size of a nickel.
Pour in half of the buttermilk and use a fork to mix until you have a shaggy dough. Add more as you need. Do not overmix. Flour your hands and turn dough onto lightly floured surface (it’s okay to have small unmixed flour at the bottom of the bowl) and gently bring dough together until more cohesive.
Turn the biscuit mixture onto a kitchen board. Work together with your hands on the board until a dough consistency forms and add flour as/if needed.
Using a floured rolling pin, roll dough into a round of 1/2- 1 inch thickness. (You should see streaks of shortening peeking through the dough.) If dough sticks as you roll it out, add a little flour to your dough and/or board.
Use a 2-inch biscuit cutter (or a cleaned out back of a can) to cut out 12 biscuits. Place in prepared pan. The biscuits will fit snugly and the sides will touch.
Bake until biscuits have risen and are light golden brown, about 15-18 minutes then brush biscuits with melted butter. Big mama would also sometimes cut open the centers and smear on more butter letting it melt down. Serve warm and enjoy!