Prepare the Pan and Oven: Preheat the oven to 450°F. Pour the melted butter into an 8-inch square pan or baking dish and set aside.
Prepare the Dry Ingredients: Whisk together the flour, baking powder, sugar, salt, and soda.
Prepare the Dough: Add the buttermilk and mix with a spatula or wooden spoon until well mixed. Let it stand for 5 minutes, then gently spread it in the prepared pan.
Slice the Dough: Grease or spray a bench scraper with cooking spray and cut the dough into 9 squares. Then wipe and spray the bench scraper again and redo the cuts. This gives the butter a nice path to surround the individual biscuits as they bake.
Bake the Biscuits: Bake in the preheated oven for 20 to 25 minutes or until golden brown. Let them stand for 5 minutes to give the butter more time to soak in, then slice and enjoy!