Line a 12-cup muffin tin with 10 paper liners or coat with nonstick spray. Set aside.
To make the crumb topping, combine sugars, cinnamon and salt in a medium bowl. Whisk in melted butter then add flour. Stir using a rubber spatula just until moist.
⅓ cup granulated sugar, ⅓ cup brown sugar, 1 teaspon cinnamon, ¼ teaspoon salt, ½ cup unsalted butter, 1½ cups all purpose flour
In a medium bowl, combine flour, sugar, baking powder, cinnamon, baking soda and salt.
1½ cups + 2 Tablespoons all purpose flour, ½ cup brown sugar, 2 teaspoons baking powder, 1 teaspoon cinnamon, ¼ tsp baking soda, ¼ teaspoon salt
In a separate large bowl, whisk together milk, melted butter, vanilla and eggs. Add the dry ingredients to the wet ingredients and stir using a rubber spatula until just incorporated, being careful not to over mix. The mixture will be thick.
¾ cup milk, ⅓ cup unsalted butter, 1 teaspoon vanilla extract, 2 eggs
Add the blueberries to the bowl the dry ingredients were in and toss with 2 Tablespoons of flour. Fold them into the muffin batter to combine.
1 cup blueberries
Cover with a towel and let the batter rest for 15-20 minutes. During this time, preheat the oven to 425°F.
Use a large cookie scoop to carefull scoop the batter evenly into the prepared muffin tins almost all the way full. Sprinkle each muffin with as much crumb topping as you can fit. You can gently press it into the batter to help it stick, but down't over do it because we want to keep as much air in the batter as possible.
Bake muffins in preheated oven for 7 minutes, then reduce the heat to 350 degrees and bake another 11-14 minutes or until a toothpick inserted in the center comes out clean.
Remove from oven and allow to cool in muffin tin for 15 minutes then remove from pan and cool completely on wire rack.