Preheat the oven to 375 degrees F and grease a 24-cup nonstick muffin tin with nonstick spray. (Or a 12 cup standard muffin pan.)
Stir together the pumpkin puree, yogurt, melted butter, egg, and vanilla in a large bowl.
Stir in the flour, sugar, pumpkin pie spice, baking powder, baking soda, and salt.
Portion into the prepared muffin tin using a heaping 1 tablespoon per mini cup or about ¼ cup for each standard size muffin. Bake for 12-14 minutes for mini muffins and 16-18 for standard size muffins, or until a cake tester inserted into the center comes out clean.