In a large bowl, mix together the flour, brown sugar, baking powder, and salt.

In another bowl, combine the milk, melted butter, maple syrup, sour cream, egg, and vanilla.

Stir into the flour mixture just until moistened.

Don’t overmix.

Getting ready to bake: Fill greased muffin cups about ⅔ full with batter.

Sprinkle the crumb topping over the tops of the muffins.

Bake for 16 to 20 minutes until done.

Cool for 5 minutes before removing muffins from the pan to a wire rack to cool.