Instructions

• Preheat oven to 350°F (177°C). Line a 12-count muffin pan with cupcake liners; line 3 cups of a second muffin pan with 3 liners (or bake in batches)—this recipe makes 15 muffins. Set aside.
• Make the crumb topping: Mix the brown sugar, cinnamon, and melted butter together in a small bowl until combined. Add the flour and use a fork to gently mix until crumbs form. Place crumb topping mixture in the refrigerator while you make the muffin batter.
• Make the muffins: Whisk the flour, baking powder, baking soda, cinnamon, and salt together in a medium bowl. Set aside.
• In a large bowl using a handheld or stand mixer fitted with a paddle attachment, beat the butter and granulated sugar together on high speed until smooth and creamy, about 3 minutes. Add the eggs and beat on medium speed until incorporated. Add the sour cream and vanilla, and beat until the mixture is combined.
• With the mixer running on low speed, add the dry ingredients, followed by the milk. Batter is thick.
• Spoon approximately 3 Tablespoons of batter into each of the 15 prepared muffin cups, filling them about ⅔ full. Spoon crumb topping on each, gently pressing it down so it adheres to the batter.
• Bake for 22–24 minutes or until a toothpick inserted in the center comes out clean.
• Allow the muffins to cool for 5 minutes in the muffin pan(s), then transfer to a cooling rack to continue cooling. Let them cool for at least 15 minutes before icing.