Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a large mixing bowl, whisk together the flour, protein powder, baking powder, and salt.

Using a pastry cutter or two knives, cut the cold butter into the dry mixture until it resembles coarse crumbs.

Add the Greek yogurt and stir until the dough just begins to come together.

Gently fold in the milk one tablespoon at a time if the dough is too dry to hold its shape.

Turn the dough onto a lightly floured surface and pat into a 1-inch thick rectangle.

Cut into 8 rounds using a 2.5-inch biscuit cutter and place on the prepared baking sheet.

Bake for 12 to 15 minutes or until the tops are golden brown and the biscuits have risen.