½cup(113 g or 1 stick) unsalted butter, melted and slightly cooled
2large eggs, room temperature
½cup(120 ml) whole or low-fat milk, room temperature
¼cup(60 g) sour cream or plain yogurt, room temperature
1teaspoonvanilla extract
Instructions
Preheat oven to 400° F. Line a muffin tin with paper liners and set aside.
Make the streusel by whisking together the flour, brown sugar, sugar and cinnamon. Pour in melted butter and mix with a fork until small clumps form. Don’t over-mix or it will become a paste. Mix just until it’s no longer dry. Set aside.
In a medium bowl, whisk together the dry ingredients–flour, baking powder, baking soda, salt and cinnamon. Set aside.
In a large bowl, mix together the granulated sugar and melted butter. Add the eggs. Mix until well combined. Add milk, sour cream and vanilla extract, then mix again until incorporated.
Add half the flour mixture to the bowl of wet ingredients and mix just until combined (avoid over mixing). Add remaining flour mixture. Stir just until combined.
Transfer batter to prepared muffin tin filling each cup almost to the top (I like to use an ice cream scoop for this step). Sprinkle streusel over the top.
Bake at 400° F for 18 to 20 minutes. Muffins are done when the tops are golden and a toothpick inserted in the center of one of the muffins comes out with little to no crumbs. Allow muffins to cool in the pan for 5 minutes. (I like to turn the muffins on their side in the pan so the bottoms don’t get soggy). Transfer to a wire rack.
Notes
Glaze: To make a glaze, whisk together 1/2 cup confectioners' sugar with 1 tablespoon milk and 1/2 teaspoon vanilla. Drizzle over the cooled muffins.Store in an airtight container at room temperature for up to 5 days.Freeze for up to 3 months.