Step 1

Preheat oven to 425°F (218°C). Spray a 12-count muffin pan with nonstick spray or line with cupcake liners. Set aside.

Step 2

In a large bowl, whisk the flour, baking powder, baking soda, cinnamon, and salt together. Set aside.

Step 3

In a large bowl using a handheld or stand mixer fitted with a paddle attachment, beat the butter on high speed until smooth and creamy, about 1 minute. Add the brown sugar and beat on high until creamed, about 2 full minutes. Scrape down the sides and bottom of the bowl as needed. Add the eggs, sour cream, and vanilla extract. Beat on medium speed for 1 minute, then turn up to high speed until the mixture is combined. Scrape down the sides and bottom of the bowl as needed.

Step 4

Pour the dry ingredients into the wet ingredients and beat on low speed until just about combined. Add the milk and continue to beat on low until combined.

Step 5

Spoon the batter evenly into each cup or liner, filling each all the way to the top. Bake the muffins for 5 minutes at 425 then, keeping the muffins in the oven, reduce the oven temperature to 350°F (177°C). Bake for an additional 15-18 minutes or until a toothpick inserted in the center comes out clean. The total time these muffins take in the oven is about 22-23 minutes, give or take. Allow the muffins to cool for 5 minutes in the muffin pan, then transfer to a wire rack to continue cooling.

Step 6

Glazed muffins stay fresh stored in the refrigerator for 1 week, unglazed muffins stay fresh stored at room temperature for a few days– then transfer to the fridge for up to 1 week.