Preheat the oven to 375°F (190°C) and line a muffin tin with paper liners.

In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt.

In another bowl, mix the milk, melted butter, eggs, and vanilla extract until combined.

Pour the wet ingredients into the dry ingredients and stir until just combined. Gently fold in the blueberries.

In a small bowl, mix together the flour, brown sugar, and cinnamon.

Add the cold cubed butter and use your fingers or a fork to mix until crumbly.

Divide the muffin batter evenly among the prepared muffin cups.

Sprinkle the crumble topping generously over each muffin.

Bake for 18-20 minutes or until a toothpick inserted into the center comes out clean.

Allow to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.