Preheat your oven to 425°F (218°C). Line a 12-cup muffin tin with paper liners or generously spray with non-stick cooking spray.
In a large bowl, whisk together the flour, baking powder, baking soda, and salt.
Toss your blueberries with 1 tablespoon of the flour mixture to prevent them from sinking during baking.
In a separate bowl, whisk the sugar and melted butter until well combined. Add eggs one at a time, beating well after each addition. Stir in buttermilk, vanilla extract, and lemon zest until smooth.
Pour the wet ingredients into the dry ingredients and fold gently with a spatula just until combined. You should still see a few streaks of flour. Gently fold in the flour-coated blueberries.
In a small bowl, combine the flour, sugar, and cinnamon for the topping. Cut in the cold butter using a pastry cutter or your fingertips until the mixture resembles coarse crumbs. Refrigerate until ready to use.
Using an ice cream scoop or large spoon, divide the batter evenly among the muffin cups, filling them to the top. Sprinkle each muffin with the crumb topping.
Bake at 425°F for 5 minutes, then reduce the oven temperature to 350°F (175°C) without opening the door and continue baking for 15-20 minutes more. Muffins are done when a toothpick inserted in the center comes out clean.