1 stick butter
1/2 c. oil
1 pkg. marshmallows
1 lg. pkg. M & M's
1 lg. bowl (24 cups) popped popcorn

Spray 9 x 12 inch pan with cooking spray. Melt marshmallows, butter and oil together. Pour over popcorn in large bowl, mix. Add M & M's and mix well. Spray hands with cooking spray and press mixture into pan. Refrigerate. Cut into squares and serve.