Preheat your oven to 475 degrees (F). Generously grease a 9-inch pie plate; set aside.
In a large mixing bowl, combine the all-purpose flour, baking powder, granulated sugar, salt, garlic powder, and black pepper. Whisk well to combine.
Add in the rosemary and Parmesan cheese, folding gently to distribute.
Add the cold butter pieces and toss to coat. Use a pastry blender or two forks to work the butter into the mixture until it resembles coarse crumbs.
Pour in the half and half and mix until just combined.
Sprinkle flour on a clean surface and scoop batter onto it, forming mounds.
Brush the tops and sides of the biscuits with melted butter.
Bake for 8 minutes, then lower the temperature and bake for another 14 to 15 minutes until golden brown.
Cool on a rack for 5 minutes. If desired, sprinkle with extra Parmesan cheese before serving.
