- Preheat oven to 400 degrees F (200 degrees C). Lightly grease a 12 cup muffin pan.
- Thaw, deseed and cube the squash.
- In a medium saucepan with enough water to cover, boil squash 20 minutes, or until tender. Remove from heat, drain, and puree in a food processor.
- In a large bowl, whisk together flour, baking powder, sugar, salt and pumpkin pie spice.
- In a medium bowl, thoroughly mix together milk, egg and butter.
- Stir in squash. Fold the squash mixture into the flour mixture just until moistened.
- Spoon the batter into the prepared muffin pan, filling cups about 1/2 full.
- Bake 20 minutes in the preheated oven, or until a toothpick inserted in the center of a muffin comes out clean.
- Remove from muffin pan and cool on a wire rack