Streusel-topped Blueberry Muffins

Streusel-topped Blueberry Muffins
Recipe from Vintage Victuals

Muffins:
1/3 cup sugar
1/4 cup unsalted butter, softened
1 egg
2 1/3 cups all-purpose flour
4 tsp baking powder
1/2 tsp salt
1/2 tsp cinnamon
1 cup milk
1 tsp vanilla extract
1 1/2 cups blueberries

Topping:
1/2 cup sugar
1/3 cup flour
1/2 tsp cinnamon
1/4 cup unsalted butter, softened

Preheat oven to 375 degrees and line 18 muffin cups with liners or spray with baking spray. Mix together butter and sugar in mixing bowl until light and fluffy. Add egg and vanilla and beat well. In a separate bowl, combine flour, baking powder, cinnamon and salt. Add flour mixture in 4 additions, alternating with milk, mixing until just combined. Stir in blueberries. Spoon mixture into prepared muffin tins, filling each cup about 2/3 of the way full.

In a separate bowl, mix sugar, flour, and cinnamon. Cut butter into small pieces and cut in with a pastry blender until mixture forms a crumbly topping. Top each muffin cup with a spoonful of topping mix until evenly distributed.

Bake about 25 minutes until the muffins are golden brown.