Butter a 10 inch tube pan or a Bundt pan.
In a microwave safe bowl, combine the marshmallows, caramels and butter. Microwave, uncovered, on high for three minutes or until melted, stirring occasionally. Place the popcorn in a large bowl, pour the caramel mixture over the popcorn and mix well. Stir in the peanuts and M&Ms. Press into the prepared pan. Cool until firm. Remove from pan. Cut with a serrated knife.
You can vary the color of the M&M’s for the holidays. Use red, white and blue for Memorial Day and the Fourth of July. Use pastels for Easter. Use red and green for Christmas. You could also make this for graduation using school colors.