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 overmix 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, and salt. Set aside.

In a large bowl, combine granulated sugar and lemon zest. Rub the mixture between your fingers to release the oils. Add melted butter and 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 and frozen raspberries. Gently stir with a rubber spatula or spoon. It’s okay if the batter turns a little pink. It will go away when baked.

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 20 to 22 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.

For the glaze, whisk together the confectioners’ sugar and lemon juice. Use a spoon to drizzle over the cooled muffins.