3/4 cup all-purpose flour
2 tablespoons light brown sugar
2 tablespoons granulated sugar
4 tablespoons unsalted butter, melted
1/4 teaspoon vanilla extract
Pinch of salt
Using a fork, mix all ingredients together until well combined. Set aside.
2 1/4 cups all-purpose flour
2 teaspoons baking powder
1 teaspoon baking soda
Pinch of salt
2 large eggs
1/2 cup buttermilk
1/2 cup firmly packed light brown sugar
1/2 cup granulated sugar
1 teaspoon vanilla extract
1/2 teaspoon lemon zest (optional)
1/2 cup unsalted butter, melted
3/4 to 1 cup blueberries
Preheat oven to 400°. For crisper edges, grease a standard muffin pan. For softer edges, use liners in each cup instead.
Whisk together flour, baking powder, baking soda and salt in a medium-sized bowl. Set aside.
In a large bowl, lightly beat eggs. Stir in buttermilk. Add both sugars and mix until combined. Stir in vanilla and lemon zest. Stir in melted butter. Add flour mixture in two to three portions. Mix until there are still streaks of flour remaining. Stir in blueberries, mixing just until combined.
Scoop about 1/4 cup of batter into each cup of prepared pan. This should fill each cup almost to the top. Sprinkle tops of each muffin with crumb mixture.
Bake for 14 to 16 minutes, or until a pick inserted into the center comes out with moist crumbs. Cool in pan on wire rack. Enjoy!