Preheat and prep: Heat the oven to 350°F (175°C). Line a 12-cup muffin pan with liners or lightly grease each well.

Make oat flour: Add rolled oats to a blender and blitz until very fine. You’ll need about 1 cup of oat flour after blending (start with 1 heaping cup of oats).

Mix dry ingredients: In a large bowl, whisk oat flour, 3/4 cup whole wheat flour, 1 scoop (about 25–30g) protein powder, 1 1/2 teaspoons baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon salt, and 1–2 teaspoons cinnamon. Add a pinch of nutmeg if you like warmth.

Whisk wet ingredients: In a separate bowl, whisk 2 large eggs, 1/2 cup Greek yogurt, 1/2 cup unsweetened applesauce, 1/3 cup pure maple syrup, 2 teaspoons vanilla extract, 3 tablespoons oil, and 1/4 cup milk until smooth.

Combine gently: Pour wet ingredients into the dry. Stir with a spatula just until the flour disappears. If the batter feels very thick (protein powders vary), add 1–2 tablespoons more milk. It should be thick but scoopable, not paste-like.

Fold in add-ins: If using nuts, raisins, or chocolate chips, fold in up to 1/2 cup total. Don’t overmix.

Fill the pan: Divide batter evenly among the muffin cups, filling each about 3/4 full. For a little sparkle, sprinkle the tops with a pinch of cinnamon sugar or oats.

Bake: Bake for 16–20 minutes, or until the tops spring back and a toothpick comes out mostly clean with a few moist crumbs. Start checking at 16 minutes.

Cool: Let muffins rest in the pan for 5 minutes, then transfer to a rack to cool completely. This helps set the structure and keeps them tender.

Finish and enjoy: Serve warm or at room temperature. If you like, drizzle a touch of warm maple syrup over a split muffin for extra coziness.