Preheat the oven to 400 degrees. Coat a 12-cup muffin pan with cooking spray or line with paper liners.
To prepare the batter, in a large bowl, whisk together the 2 cups of flour, 1 cup of sugar, baking powder, and 1/2 teaspoon salt. Set aside.
In a separate bowl, lightly whisk the eggs. Whisk in the melted butter, milk, and vanilla extract until blended. Add the egg mixture to flour mixture and stir until just combined (the batter will be lumpy). Fold in the blueberries.
To prepare the streusel topping, in a medium bowl combine the 1/4 cup flour, 2 tablespoons brown sugar, 2 tablespoons granulated sugar, cinnamon, and 1/8 teaspoon salt. Add the butter and use a pastry cutter or fork to create a crumbly topping.
Spoon the batter into the prepared pan, filling each cup (use an ice cream scoop or large cookie scoop to fill the cups with ease).
Top with the streusel topping, about 1 heaping tablespoon of crumble per muffin (it may seem like a lot of streusel, but it spreads out as the muffins rise).
Bake for 18 to 20 minutes, until a wooden pick comes out clean or with a few moist crumbs.
Cool the muffins, in the pan, on a wire rack for 8 to 10 minutes before removing the muffins from the pan.