Preheat oven to 350° and line muffin tin with liners. Make crumb topping: In a medium bowl, combine flour, sugars, pumpkin pie spice, and salt. Stir in melted Cannabis butter until crumbs form.
In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, cinnamon, and pumpkin pie spice. Add pumpkin, eggs, more cannabis butter, sour cream, and vanilla, and mix until combined.
Divide batter into muffin liners. Top each with crumb topping.
Bake until muffins are golden brown and a toothpick comes out clean, about 25 minutes. Let muffins cool in pan, then serve.