Preheat oven to 400 degrees Fahrenheit and line a baking sheet with parchment paper.

Whisk together the self-rising flour, whey protein isolate, salt, and garlic powder in a large mixing bowl.

Incorporate the cold cubed butter into the dry ingredients using a pastry cutter until the texture resembles coarse crumbs.

Add the Greek yogurt and skim milk to the bowl, stirring gently until a cohesive but shaggy dough forms.

Transfer the dough to a lightly floured surface and fold it over itself four times to create structural layers.

Pat the dough to a uniform 1-inch thickness and cut into 6 rounds using a 3-inch biscuit cutter.

Arrange the biscuits on the baking sheet and bake for 15 to 18 minutes until the tops are golden brown.

Cool the biscuits on a wire rack; once room temperature, wrap individually in foil or plastic wrap for freezer storage.