Cinderella Pumpkin Muffins

1/3 cup butter
2/3 cup sugar
2 eggs
1 cup Cinderella pumpkin (or other winter squash)
1 teaspoon vanilla
1-1/3 cups flour
1/4 teaspoon baking soda
2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup chopped walnuts

Cream butter and sugar together.
Add eggs, processing until smooth.
Add pumpkin and vanilla, processing until smooth.
Mix in a separate bowl – flour, baking soda, baking powder and salt.
Add to wet mixture in batches, processing until smooth. Stir in walnuts.
Pour into 12 muffin cups.
Bake about 20 minutes at 350 degrees.