1 pound yellow summer squash, cut into 1-inch slices
1/2 cup butter, melted
1 large egg, lightly beaten
1-1/2 cups all-purpose flour
1/2 cup sugar
2-1/2 teaspoons baking powder
1/2 teaspoon salt
Place 1 in. of water in a saucepan; add squash. Bring to a boil. Reduce heat; cover and simmer for 5 minutes or until tender. Drain and mash; stir in the butter and egg. In a bowl, combine the flour, sugar, baking powder and salt. Stir in the squash mixture just until moistened.
Fill greased muffin cups three-fourths full. Bake 375° for 20-25 minutes or until a toothpick inserted in the center comes out clean. Cool for 5 minutes before removing from pan to a wire rack.