Preheat oven to 375°F (190°C). Line a muffin tin with paper liners.
In a large bowl, whisk together flour, sugar, brown sugar, baking powder, baking soda, and salt.
In another bowl, mix melted butter, milk, and vanilla extract. Add to dry ingredients and stir until just combined.
Divide batter evenly among muffin cups.
For the crumb topping, mix brown sugar, flour, melted butter, and cinnamon until crumbly. Sprinkle over muffin batter.
Bake for 20 minutes or until a toothpick inserted into the center comes out clean. Cool on a wire rack.