Preheat your oven to 350°F. While it heats, combine the sliced peaches, vanilla protein powder, tapioca starch, lemon juice, and ground cinnamon in a bowl, stirring gently until the peaches are evenly coated. The protein powder and starch will help thicken the filling as it bakes, while the cinnamon adds warmth and the lemon juice brightens the flavor. Pour the mixture into a ramekin or small baking dish (about 8 oz capacity works well).
Bake the peach filling in the preheated oven for 15 minutes. This head start allows the peaches to release their juices and begin breaking down, creating a more cohesive filling. While this bakes, prepare your topping.
While the peaches bake, combine the gluten-free flour, protein powder, and baking powder in a separate bowl, whisking together to ensure the baking powder is evenly distributed and there are no lumps. I always use fresh baking powder for this recipe—it makes a noticeable difference in the rise and texture of the topping, giving it a fluffier, more cake-like crumb.
Add the yogurt, almond milk, and melted butter to the dry mixture from Step 3, stirring gently until just combined into a thick, biscuit-like dough. Be careful not to overmix—a few lumps are fine and will actually result in a more tender topping. The mixture should be thick and hold together but still be dollop-able. I prefer using thick Greek yogurt (like Fage 0%) because it creates a denser, more cohesive dough that doesn't spread too much during baking.
Remove the ramekin from the oven and carefully spoon the dough from Step 4 onto the hot peach filling, spacing the dollops so some fruit shows through (this looks more like a traditional cobbler). Return to the oven and bake for an additional 20 minutes, until the topping is golden brown and springs back lightly when touched.
Remove from the oven and let cool for 5 minutes—this allows the filling to set slightly while the topping remains warm and fluffy. Serve immediately, optionally topped with a scoop of vanilla ice cream or Greek yogurt for extra protein and cooling contrast.