Preheat oven to 200°F (93°C). Line a baking sheet with parchment paper for later use. Checkpoint: Your oven is ready when it reaches 200°F.

Pour 1 pound white chocolate chips into a large Pyrex or oven-safe glass dish. Checkpoint: All chips are in one dish, spread in an even layer.

Place the dish in the preheated 200°F oven for 10–15 minutes, stirring halfway through. The chocolate should be completely melted and smooth (it will look glossy and easy to stir). Checkpoint: The chocolate is ready when there are no lumps and it flows easily when you stir it.

Add 5½ tablespoons crunchy peanut butter to the melted chocolate while the dish is still in the warm oven. Let it sit in the oven for 2–3 minutes without stirring. Checkpoint: The peanut butter should start to soften from the heat.

Remove the dish carefully from the oven using an oven mitt (it will be hot). Stir the chocolate and peanut butter together until fully combined and smooth. Checkpoint: The mixture is creamy and there are no swirls of peanut butter visible.

Add 1 cup miniature marshmallows to the warm chocolate-peanut butter mixture. Stir gently and constantly for 1–2 minutes until the marshmallows are coated and beginning to melt slightly into the chocolate. Checkpoint: Every marshmallow is coated in chocolate and the mixture looks glossy.

Add 1 cup unsalted dry roasted peanuts to the mixture. Fold them in gently for 30–45 seconds. Checkpoint: Peanuts are evenly distributed throughout.

Add 1½ cups Rice Krispies cereal to the mixture. Fold gently with a spatula or sturdy spoon for 1–2 minutes, making sure all cereal is coated but not crushed. The mixture should feel thick and hold together when pressed. Checkpoint: The cereal is evenly coated and the mixture is thick enough to hold its shape.

Line a large cutting board or baking sheet with wax paper. Using a small teaspoon, drop rounded spoonfuls of the mixture onto the wax paper, spacing them about 1 inch apart. This should take 3–5 minutes. Checkpoint: All mixture is portioned out and looks like small clusters.

Let the treats sit at room temperature (68–72°F is ideal) for 2 hours. They should firm up and become firm to the touch but still slightly chewy inside. Do not disturb them during this time. Checkpoint: When you gently press one with your finger, it feels set on the outside but yields slightly inside.

Transfer the completely set treats to an airtight container. Store at room temperature for up to 5 days, or refrigerate for up to 2 weeks, or freeze for up to 3 months. If freezing, separate layers with parchment paper.