Preheat & Prep. Set your oven to 350°F (175°C). Line a muffin tin with paper liners or lightly grease it.
Mix Dry Ingredients. In a large bowl, combine oats, protein powder, cinnamon, baking powder, and any mix-ins you like (nuts, raisins, etc.).
Whisk the Wet Mix. In another bowl, whisk together honey or maple syrup, eggs, applesauce, vanilla, and milk until smooth.Combine & Stir Gently. Combine & Stir Gently. Pour the wet mixture into the dry bowl and stir just until combined. (Overmixing = dense muffins, so go easy here.)
Fill the Muffin Cups. Spoon the batter evenly into your prepared muffin tin, filling each about two-thirds full.
Bake to Perfection. Bake for 15–20 minutes, or until the tops are golden and a toothpick inserted into the center comes out clean.Your kitchen should smell like a cozy cinnamon bakery by now.
Cool & Enjoy. Let the muffins rest in the pan for 5 minutes before transferring them to a wire rack to cool completely.