Preheat the oven to 375°F. Coat the muffin tin with cooking spray or butter (optional: use muffin paper liner).
In a large bowl: add in the flour, baking powder, baking soda, salt, cinnamon and mix everything together.
1 cup all-purpose flour, 2 tsp ground cinnamon, 1 ½ tsp baking powder, ½ tsp salt, ½ tsp baking soda
Add the eggs, raisins, oats, milk, brown sugar, vanilla extract, and oil. Use a spatula and mix until all ingredients are well combined. Let the batter rest for 10 minutes.
1 ½ cup rolled oats or quick oats, 1 cup milk (low fat, fat free or full), 1 cup raisins, ½ cup brown sugar, ½ cup vegetable or canola oil , 1 tsp vanilla extract, 2 large eggs
Bake for 20-22 minutes or until golden brown. Let the muffins cool in the tin for about 5 minutes and then transfer them to a baking rack to finish cooling completely.