I think this is the treat recipe I make. It looks right, from memory. I do mine on the stove though. They don't last long around here!
http://www.tasteofhome.com/Recipes/Cheerio-Treats
Here are the ingredients
* 3 tablespoons butter
* 1 package (10-1/2 ounces) miniature marshmallows
* 1/2 cup Jif® Peanut Butter
* 5 cups Cheerios
* 1 cup milk chocolate M&M's