Creating these Wholesome Cinnamon Breakfast Muffins is straightforward. Just follow these easy steps:

1. Preheat Oven: Start by preheating your oven to 375°F (190°C). Line a muffin tin with paper liners or spray with cooking spray.
2. Mix Dry Ingredients: In a large mixing bowl, whisk together the whole wheat flour, rolled oats, brown sugar, baking powder, cinnamon, and salt until well combined.
3. Combine Wet Ingredients: In another bowl, beat the egg, then mix in the milk, vegetable oil, and vanilla extract.
4. Combine Mixtures: Pour the wet ingredients into the dry ingredients and stir gently. Mix until just combined; do not overmix.
5. Add Nuts (Optional): If you’re adding nuts, fold them into the batter until they’re evenly distributed.
6. Fill Muffin Cups: Spoon the batter into the prepared muffin cups, filling them about ¾ full to allow for rising.
7. Bake: Place the muffin tin in the preheated oven and bake for about 20 to 25 minutes. They are done when a toothpick inserted in the center comes out clean.
8. Cool: Remove the muffins from the oven, let them cool in the pan for about 5 minutes, then transfer them to a wire rack to cool completely.

By following these steps, you will be left with a batch of delicious cinnamon muffins, ready to be enjoyed!