1. Preheat your oven to 375 F (190 C). Line a 12-cup muffin tin with paper liners or lightly grease it with cooking spray.

2. In a large mixing bowl, whisk together the whole wheat flour, protein powder, granulated sugar, baking powder, baking soda, and salt until evenly distributed.

3. In a separate medium bowl, whisk together the almond milk, unsweetened applesauce, melted coconut oil, egg, and vanilla extract until well combined and smooth.

4. Pour the wet ingredients into the bowl with the dry ingredients. Stir gently with a spatula or wooden spoon until just combined. Be careful not to overmix; a few lumps are fine.

5. If using chocolate chips or chopped nuts, gently fold them into the batter now, distributing them evenly.

6. Divide the batter evenly among the 12 prepared muffin cups, filling each cup about two-thirds full.

7. Place the muffin tin in the preheated oven and bake for 18-22 minutes, or until a wooden skewer or toothpick inserted into the center of a muffin comes out clean. The tops should be golden brown and spring back when lightly touched.

8. Remove the muffin tin from the oven and let the muffins cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.