For the biscuits: Line a baking sheet with parchment paper and preheat oven to 450 degrees. Grind whole pepper berries in a spice grinder until fine. In a medium bowl, combine 1/2 tsp. of the ground pepper berries with the flour, Four Cheese, baking powder, sugar, and salt. Add butter and cut it in with a pastry cutter or two knives until the pieces are no larger than a pea. Add 1 1/4 cups of the milk and stir gently until all the flour is moistened. Turn out the dough onto a floured work surface. Flour the top of the dough. Knead the dough briefly by folding it over itself and pressing down gently until the dough comes together as a coherent mass. For the first few folds, it's easier to use a bench scraper to lift and fold the dough. Add more flour if the dough is too wet, but avoid adding so much that the dough becomes stiff; it should be soft dough. Roll the dough to a thickness of about ¾ inch. Cut out biscuits using a biscuit cutter. Place the biscuits on the prepared baking sheet. If you want biscuits that are crisp all the way around, leave them separated. If you prefer soft sides, arrange the biscuits so their sides are just barely touching. Re-roll any scraps remaining from cutting out the biscuits and cut more biscuits. Brush the tops of the biscuits with the remaining 2 Tbsp. milk and sprinkle with some of the remaining ground pepper berries. Bake the biscuits until nicely browned, about 12 to 15 minutes.
For the butter: Combine butter and the Parmesan Pesto Sprinkle in a small bowl and mix thoroughly to distribute the herbs throughout the butter. Refrigerate if you won't be using it in an hour or so. This is best if it's made at least an hour ahead. This gives the herbs a little time to hydrate and soften, so the texture is better and the flavor is a little more pronounced.