Begin by preheating the oven to 250 degrees Fahrenheit.
Next prep a cookie sheet by lining it with parchment paper.
Melt the butter in a small bowl in the microwave and then set it aside.
In a large bowl combine the cereal, crackers, and pumpkin seeds.
To the melted butter add the Worcestershire sauce, garlic powder, and hot pepper sauce. Stir the mixture together.
Drizzle the butter mixture over the chex mix.
Use your hands to toss the mixture making sure to coat all of the ingredients.
Place the chex mix on the prepared cookie sheet. Spread the mix out on the cookie sheet.
Bake at 250 degrees Fahrenheit for 1 hour, flip and stir the mixture after baking for 30 minutes.
Remove from the oven and allow to cool for 15 minutes.
Once mixture is cooled add in the M&M's and stir to combine.
Store the chex mix in an air tight container or a zip loc bag.