Preheat the oven to 450°F. Add the butter to an 8x8-inch baking dish then place it in the oven while it preheats to let the butter melt. Once the butter is melted, remove it from the oven and let the dish cool while you make the dough.
Add the flour, baking powder, sugar, salt, garlic powder, and Old Bay to a medium bowl. Mix together, then add the grated cheese and mix until all pieces are coated in flour and everything is well combined.
Pour in the buttermilk and stir until mostly combined, being careful not to overwork the batter. It’s ok if there are still a few pockets of raw flour.
Spoon the dough into the pan on top of the melted butter and use a spatula (or your hands) to evenly spread the dough out to the edges.
Use a butter knife or steak knife to cut the unbaked dough into 9 squares (3x3 pattern) or 16 squares (4x4 pattern). Tilt the pan to make sure butter gets into all of the cuts.
Bake for 25-30 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out clean.
While the biscuits bake, melt the butter for the topping either in the microwave or a small saucepan on the stove.
Mix in the garlic powder, Old Bay, and parsley until combined.
When the biscuits are done, remove them from the oven and immediately brush them all over with the garlic Old Bay butter.
Allow the butter to absorb fully and let the biscuits cool slightly before cutting and serving. The biscuits are best served while they’re still warm.
