Preheat the oven to 400 degrees. Dice the 6 tablespoon butter into ¼” cubes and return them to the fridge until ready to use. Line a baking tray with parchment paper or a silicon baking mat.
Mix the 2 cups bread flour, 8 tablespoon unflavored collagen powder, 1.5 teaspoon baking powder, ½ teaspoon salt, and 2 tablespoon sugar in a large bowl or the base of a stand mixer.
Add the butter to the dry ingredients. Use a fork, pastry cutters, or your hands to “cut” the butter into the flour mixture until a sand-like texture emerges. You can try to do this with the paddle attachment on the stand mixer but I find it easier to just use my hands.
In a small bowl, mix the 1 egg and ¾ cup Greek yogurt until well combined. Add this to the flour and butter mixture and mix until a dough forms. Mix with either a wooden spoon, a paddle attachment on the stand mixer, or your hands. Mix until the dough comes cleanly off the sides of the bowl. If it's too sticky, mix in more flour (2 tablespoons at a time).
Dump this out onto a floured surface and knead about 10 times. The dough should just come together, then stop mixing. After kneading, roll it out to about ½”-¾” thick.
Use an upside-down cup or a round cookie cutter to cut out nine 3”-4” diameter circles. You'll have to reroll the extra dough between cuts to get all 9 biscuits.
Place them on a baking tray and bake for 15 minutes or until golden brown.