In a medium bowl, whisk together both sugars, cinnamon, salt and flour. Add melted butter and fluff with fork until mixtures creates crumbs. Set aside.
!to make the muffins
Preheat oven to 350 degrees F.
Line a muffin pan with paper liners. Set aside.
In a large mixing bowl, whisk together the dry ingredients (flour, baking soda, baking powder, salt and cinnamon).
In another mixing bowl, mix together the wet ingredients (pumpkin puree, oil, yogurt, vanilla and eggs). Add sugar and mix well.
Stir in the wet ingredients into the dry ingredients. Mix only until combined. Do not overmix.
Scoop the batter into the prepared muffin pan. I use an ice cream scoop and place 1 scoop of batter per muffin liner.
Sprinkle streusel topping on top of each muffin.
Bake 18 to 22 minutes or until the toothpick inserted into a center of each muffin comes out clean.