Preheat your oven to 325° F. Line a 9x13 inch baking pan with parchment paper for easy removal, or alternatively, line 24 cupcake molds with paper liners to make individual portions.

On a rimmed baking sheet, combine the melted salted butter and vanilla extract. Add the corn cereal squares, rice cereal squares, mini pretzels, and assorted nuts. Sprinkle the ground cinnamon and white sugar evenly over the mixture, then toss everything well to coat thoroughly. Spread the mixture into an even layer and bake for 15 minutes, tossing halfway through, until the mix is lightly toasted and fragrant. This will give the base an amazing crunch.

While the cereal mix is toasting, melt the honey and smooth peanut butter together in a large pot over low heat, stirring often, until completely smooth (about 5 minutes). Remove the pot from heat, then add the toasted Chex mix from Step 2. Toss well to combine, ensuring that everything is evenly coated. Spread this mixture into your prepared pan or spoon evenly into cupcake liners for individual treats. I like to gently press the mixture down so it sticks together better when chilled.

Melt the semi-sweet chocolate chips together with the coconut oil (if using) in a microwave-safe bowl in 30-second intervals, stirring after each, until smooth and melted. Pour the chocolate mixture over the cereal bars, spreading it in an even layer to cover all of the surface. I always recommend using coconut oil here if you like a glossier, softer chocolate top—totally optional!

Chill the assembled cereal bars in the refrigerator for about 1 hour, or until the chocolate topping has set firmly. Let the bars sit at room temperature for 15-20 minutes before cutting to make slicing easier. Cut into bars or squares and keep refrigerated until ready to serve. For an extra treat, you can finish them with a sprinkle of sea salt before the chocolate sets.