Preheat your oven to 350°F (175°C) and prepare a muffin tin by lining it with cupcake liners or lightly greasing each cup.

In a large mixing bowl, whisk together rolled oats, brown sugar, baking powder, baking soda, cinnamon, and salt.

Stir in grated carrots, applesauce (or yogurt), vegetable oil (or melted coconut oil), and vanilla extract into the dry mixture.

If desired, fold in walnuts or raisins at this stage.

Divide the batter evenly into the prepared muffin cups, filling each about two-thirds full.

Bake for 15-20 minutes until the tops are golden brown and a toothpick comes out clean.

Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.