Lemon Blueberry Muffins with a Lemon Crumble Topping

INGREDIENTS

2 1/2 cups

unbleached, all-purpose flour

1/2 tsp

salt

2 1/2 tsp

baking powder

1/4 tsp

baking soda

3/4 cup

granulated sugar

1 cup

sour cream (8-ounces)

1/2 cup

unsalted butter, melted and cooled

1 tsp

vanilla extract

1 tbsp

lemon zest (about 1 lemon)

1/4 cup

fresh lemon juice (about 2 lemons)

large eggs, lightly beaten

1 1/2 cups

fresh blueberries

4 tbsp

unsalted butter, melted

3/4 cup

unbleached all-purpose flour

1/3 cup

granulated sugar

1 tbsp

fresh lemon juice

zest of 1 lemon

1/2 cup

powdered sugar

juice of 1/2 a lemon (more or less)