In mixing bowl, stir together flour, baking powder, 1 t. pumpkin pie spice, and salt; set aside. In a separate bowl, cream together 1/2 cup sugar, shortening and egg. Mix in pumpkin and vanilla. Add flour mixture and milk alternately to the creamed mixture, beating well. Fill 12 greased muffin cups 2/3 full (don't use paper baking cup liners). Bake at 350 for 20 to 25 minutes or until golden brown. Combine 1/2 cup sugar and cinnamon. While muffins are still hot out of the oven, submerge in melted butter, and then roll in sugar ‘n spice mixture until coated. Serve warm.