Preheat oven to 250 F.
In a large bowl, combine pretzels, crackers and peanuts.
In a large saucepan, combine sugar, butter and corn syrup. Bring to a boil over medium heat.
Boil for 5 minutes. Remove from heat, stir in vanilla and baking soda. The mixture will foam.
Pour over pretzel mixture and stir until coated.
Spread onto a greased or parchment paper-lined rimmed baking sheet. Bake for 45 minutes.
Break apart and toss with M&M’s while still warm.
Cool completely and store in an airtight container.