Preheat the oven to 350°F.
Line muffin tin with paper cups or spray with a baking spray. Set aside.
In a medium mixing bowl, whisk together flour, brown sugar, baking powder, cinnamon and salt.
In another bowl, whisk together eggs, milk, oil and vanilla extract.
Add the dry ingredients to the wet ingredients and stir together just until combined. Batter should be lumpy. Do not overmix!
Scoop the batter into the muffin tin. It should fill each cup about ¾ full.
In a large mixing bowl, whisk together granulated sugar, brown sugar, cinnamon, and flour. Add melted butter and stir in until it all comes together. Fluff with a fork to make a mixture that resembles coarse crumbs.
Sprinkle the topping on top of the batter of each muffin. Use all of the mixture even though it may seem like a lot of topping.
Bake the muffins for 15 to 18 minutes or until the toothpick inserted into each muffin comes out clean.
Let the muffins cool in the pan for 10 minutes, then transfer onto a cooling rack to cool completely.