Mina's Pumpkin Muffins

1 Duncan Hines Spice Cake Mix (just the mix--don't follow instructions on box)
1 Libby's canned pumpkin (15oz)

1 cup raisins (optional)

1/2 cup water

Mix all ingredients and put in greased muffin pan or cupcake liners

Bake at 325 for 10-15 minutes