Preheat your oven to 350°F (175°C) and line a muffin tin with liners or grease it lightly.
In a large mixing bowl, combine the rolled oats, protein powder, baking powder, ground cinnamon, and salt. Mix well.
In another bowl, whisk together the Greek yogurt, applesauce, maple syrup, almond milk, eggs, and vanilla extract until the mixture is smooth.
Gradually add the wet ingredients to the dry ingredients, stirring to combine until just mixed. If desired, fold in the chopped nuts and raisins at this stage.
Divide the batter evenly among the muffin cups, filling each about 2/3 full.
Bake in the preheated oven for 18-20 minutes or until a toothpick inserted in the center comes out clean.
Once baked, allow the muffins to cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.
Notes
Serve the muffins warm, optionally drizzled with a simple glaze made from powdered sugar and a splash of almond milk for a sweet touch. You can also sprinkle a pinch of cinnamon on top for added flavor and appeal!