Line an 8-inch square baking pan with parchment paper or wax paper. Set aside at room temperature. Clear some space in the freezer for this pan—you will need it later.

Melt the chocolate using the double boiler method, or do the following: add chocolate chips and peanut butter to a medium, microwave-safe bowl (large enough to add cereal later). Heat in 20-second increments until softened and melty. Stir in between heating increments, until smooth.

Add rice crisp cereal to melted chocolate mixture. Using a rubber spatula, stir and fold until well incorporated. Pour this mixture into the prepared baking pan. Using the spatula, smooth into an even layer. Tap the pan a few times to help even out the mixture.

Transfer this pan into the freezer. Freeze for 35-45 minutes, or until completely firm. Slice into 36 mini squares (6 by 6). Enjoy! Storing instructions below.