Preheat and prep: Heat your oven to 350°F (175°C).
Lightly grease a mini muffin pan or use silicone cups so the bites release cleanly.
Make oat flour (if needed): Blitz rolled oats in a blender until they’re a fine flour. Measure after blending to keep amounts accurate.
Whisk dry ingredients: In a bowl, combine 1/2 cup oat flour, 1/2 cup all-purpose flour, 1/2 cup protein powder, 1 1/2 teaspoons baking powder, 1/4 teaspoon salt, and 1/2 teaspoon cinnamon.
Mix wet ingredients: In another bowl, whisk 2 large eggs, 3/4 cup milk, 1/2 cup Greek yogurt, 2 tablespoons maple syrup, 1 teaspoon vanilla, and 2 tablespoons melted coconut oil or butter.
Combine gently: Pour the wet mixture into the dry. Stir until just combined.
The batter should be thick but pourable. If it’s too thick, add 1–2 tablespoons more milk.
Add mix-ins: Fold in 1/2 cup total of your chosen mix-ins. Keep pieces small so they bake evenly.
Fill the pan: Spoon batter into the mini muffin cups, filling each about 3/4 full.
For neat tops, smooth with the back of a spoon.
Bake: Bake 10–13 minutes until the centers set and a toothpick comes out mostly clean. They’ll spring back lightly when pressed.
Cool: Let the bites rest in the pan for 5 minutes, then transfer to a rack. This helps them firm up and stay tender.
Serve or store: Enjoy warm with a drizzle of maple syrup or a smear of nut butter, or cool completely for meal prep.