Preheat oven to 350°F and line a muffin pan with 12 cupcake/muffin liners. Mix all of the muffin ingredients until well combined and scoop into the muffin liners.
Cream together the cinnamon swirl ingredients using a hand mixer. Scoop about 1 teaspoon of the cinnamon butter mixture onto each muffin and use a toothpick to swirl it into the dough.
Bake for about 22-23 min. Mix up the glaze and drizzle over the tops of the muffins. Enjoy!