⅓cupbrown sugar(both light and dark brown sugar work)
1teaspoonground cinnamon
4Tablespoonunsalted buttersoftened to room temperature
Cinnamon Swirl
½cupbrown sugar(both light and dark brown sugar work)
2teaspoonground cinnamon
Muffins
½cupunsalted buttersoftened to room temperature
½cupgranulated sugar
2large eggsat room temperature
1teaspoonvanilla extract
¾cupbuttermilk(or substitute regular milk)
2cupsall purpose flour
1teaspoonbaking powder
½teaspoonbaking soda
1teaspoonground cinnamon
¼teaspoonsalt(use table salt or fine sea salt)
Instructions
Preheat the oven to 350°F. Line a muffin tin with muffin/cupcake liners.
Prepare the streusel by combining the all purpose flour, brown sugar, cinnamon, and softened butter in a mixing bowl. Use a large spoon, silicone spatula, or your hands to mix the mixture until it's crumbly. Set aside.
Prepare the cinnamon swirl by mixing the brown sugar and ground cinnamon in a small bowl with a spoon. Set aside.
To make the muffin batter, beat the softened butter and sugar until it is pale and fluffy, after a few minutes. Either use a large mixing bowl with a hand mixer or a stand mixer with the paddle attachment.
Add the egg and vanilla. Beat the mixture again until it’s well combined, after about 1 minute. Add the milk and mix for 30 seconds.
Add the all purpose flour, baking powder, baking soda, cinnamon, and salt. Mix with a large spoon or silicone spatula until you no longer see dry pockets of flour. Scrape the sides and bottom of the bowl to ensure everything is well mixed.
Use a cookie scoop or a large spoon to drop muffin batter into each muffin cup to fill it only about one-third to one-half full. (Don’t add too much batter yet, otherwise you won’t have enough to add on top of the cinnamon swirl.)
Sprinkle the brown sugar-cinnamon mixture evenly distributed between all the muffins.
Distribute the remaining muffin batter evenly into each muffin cup, until each one is about ¾ full. (Since the batter is thick, it's best to spoon it on top, then use spoons or your fingers to spread it evenly on the cinnamon swirl mixture.)
Sprinkle the streusel topping on top of the muffins.
Bake the muffins for 18 to 22 minutes, until a toothpick inserted into the center of the muffins comes out without any wet batter stuck to it.Enjoy!!
Notes
Fill the muffins only ¾ full. Filling them less with result in sad, short muffins. And filling them all the way to the top with batter could cause them to overflow as they bake, creating wide, flat tops.
If you don’t have buttermilk, you can make it at home by mixing ¾ cup milk with 1 tablespoon lemon juice or white vinegar and let it sit for 10 minutes to curdle.
Store cooled muffins in an airtight container at room temperature for up the 3 days.