In a large bowl, combine the pretzels, crackers and peanuts. In a large saucepan, combine the sugar, butter and corn syrup. Bring to a boil over medium heat; boil for 5 minutes. Remove from the heat; stir in vanilla and baking soda (mixture will foam). Pour over pretzel mixture and stir until coated.
Transfer to a greased 15x10x1-in. baking pan. Bake at 250° for 45 minutes, stirring every 10-15 minutes. Break apart while warm. Toss with M&M's and candy corn. Cool completely. Store in airtight containers.