Preheat your oven to 300 degrees.

Line a large baking sheet with parchment paper and set aside.

In a medium saucepan, heat butter over medium heat, until melted.

Stir in brown sugar, and heat over medium high, until it begins to simmer.

Remove from the heat and stir in vanilla.

To your baking sheet, add rice chex, pretzels, and bugles. Stir to combine and mix the ingredients.

Pour the sauce over the mixture.

Stir the mixture to coat everything in the sauce.

Bake in your preheated oven for 30 minutes, stirring halfway through.

Allow the mixture to cool slightly, and add to a large mixing bowl.

Add M&Ms and Reese’s pieces and toss together.