Preheat your oven to 425 degrees. Place the 1/2 cup of salted butter in the baking dish to melt while the oven is preheating.
In a large bowl, whisk together the flour, baking powder, sugar and salt. Using a pastry cutter or your fingers, rub or cut the cold butter into the flour mixture until it resembles coarse crumbs.
Add in the milk and mix. It will be very soft and sticky.
Turn the dough out onto a well-floured surface and knead gently for a few turns, incorporating as much four as needed until dough comes together. Pat dough its a square and cut into nine equal portions. Remove baking dish from the oven and place biscuits on top of melted butter.
Bake for 17-20 minutes or until biscuits are golden brown on top.