Pre-heat your oven to Bake at 350° F.
Stir in the granulated sugar, salt, and pure vanilla extract.
Stir in the gluten-free flour, baking soda, baking powder, cinnamon and xanthan gum (leave out the xanthan gum if your flour already has it) and mix until all the ingredients are smooth and fully combined.
Scoop the batter into baking cups lined/cooking sprayed muffin tin. I like to use a greased ice cream scoop.
Add all of the dry ingredients of the crumb topping to a small bowl and stir until fully combined. Pour in the melted butter (or coconut oil) into the dry ingredients and stir until the topping looks thick and crumbly.
Bake for 20 minutes at 350 ° F, or until a toothpick inserted into the center comes out clean. Please watch your muffins because all ovens are different.
Allow the muffins to cool. Enjoy!
Store in an air-tight container.