Preheat and Prepare. Preheat your oven to 450°F. While the oven is heating, grab a baking dish and melt the unsalted butter in it.
Mix Dry Ingredients. In a mixing bowl, combine the all-purpose flour, baking powder, sugar, and salt. Mix well.
Add Buttermilk. Pour in the cold buttermilk and stir until just combined. Be careful not to overmix; a slightly shaggy dough is what you're aiming for.
Form Biscuits. Turn the dough out onto a floured surface and gently pat it into a rectangle. Fold the dough over itself in thirds, similar to folding a letter. Repeat this process two more times.
Cut Biscuits. Roll the dough to about 1/2-inch thickness and cut the biscuits into rectangles. Place the cut biscuits into the melted butter in the baking dish.
Bake. Bake in the preheated oven for about 15-20 minutes or until the biscuits are golden brown and cooked through.
Butter Swim Magic. Witness the magic as the biscuits swim in the melted butter, soaking up all that rich flavor during the last few minutes of baking.
Serve and Enjoy. Once out of the oven, let the biscuits cool for a moment before serving. They're best enjoyed warm.