In a large bowl, combine flour, sugar, baking soda, baking powder, salt, cinnamon, nutmeg and pumpkin pie spice.
Add pumpkin puree, greek yogurt and vanilla extract; mix until well combined.
Divide batter into cupcake liners until ⅔ full.
In a small mixing bowl, combine flour, brown sugar, pumpkin pie spice and softened butter with a fork until crumbs form.
Sprinkle crumb mixture on top of muffins.
Bake for 25 minutes, or until an inserted toothpick comes out clean.
Notes
If pumpkin chocolate chip is more your thing, you could easily convert this recipe to make Pumpkin Chocolate Chip Muffins.Simply skip the crumb topping, and fold in 1 1/2 cups mini chocolate chips in the batter before scooping batter into the muffin tin. Cook as directed.