Prep your pan: Line an 8x8-inch square pan with parchment, letting some overhang for easy lifting. Lightly grease the parchment.

Measure the dry: Add puffed rice cereal to a large mixing bowl. If your protein powder has clumps, sift it in or whisk it separately to break up lumps.

Melt the base: In a small saucepan over low heat, melt peanut butter, chocolate chips, and coconut oil. Stir continuously until smooth and glossy. Don’t overheat—gentle heat prevents scorching.

Sweeten and flavor: Remove from heat. Stir in honey or maple syrup, vanilla, and a pinch of salt. Taste and adjust sweetness to your liking.

Add protein powder: Whisk the protein powder into the warm peanut butter-chocolate mixture until fully combined. It should look thick but pourable.

Combine with cereal: Pour the mixture over the puffed rice. Use a spatula to fold until every piece is coated. Work quickly; as it cools, it firms up.

Press into pan: Scrape the mixture into your prepared pan. Lightly press it into an even layer using a spatula or a piece of parchment to avoid sticking. Don’t crush the cereal.

Optional toppings: Sprinkle mini chocolate chips, chopped peanuts, or flaky sea salt on top. Gently press them in so they stick.

Chill: Refrigerate for 45–60 minutes, or until firm. For faster set, pop it in the freezer for 20–25 minutes.

Slice and serve: Lift the slab out using the parchment and cut into 12–16 bars. Enjoy cold for clean edges and extra chew.