Combine the peanut butter and butter in a large microwave-safe bowl. Melt the two together on medium power until they can be stirred smooth without any lumps. Stir in the vanilla.
Use a fine mesh sieve to sift the powdered sugar into the bowl. Stir to combine. Add the crispy rice cereal and stir until the cereal is well coated and everything is evenly mixed. Place the bowl in the fridge for 30 minutes, or in the freezer for 20 minutes.
Once slightly firm and chilled, use a small cookie scoop (about 2 teaspoons) to scoop the peanut butter dough. Use the palm of your hand to firmly pack the scoop with peanut butter before releasing it onto a plate or tray that will fit in your freezer. Once all of the peanut butter is scooped, place the plate or tray in the freezer for 30 minutes and up to overnight.
Finely chop the chocolate and the wax. Place the two in a deep microwave-safe vessel (a 2 cup glass liquid measuring cup works well here). Microwave the chocolate and wax together on medium power until they are melted and can be stirred smooth.
Remove the peanut butter balls from the freezer. Drop one into the melted chocolate and use a fork to gently stir it around and coat it in chocolate. Use the fork to lift the ball out of the chocolate. Scrape the bottom of the fork against the edge of the measuring cup to wipe off any excess chocolate, then gently slide the ball onto a piece of parchment paper. Repeat until all of the peanut butter balls are coated in chocolate.
Leave the peanut butter balls to set at room temperature for about 30 minutes, before packing them carefully into a container and storing them in the fridge or freezer until needed.
Notes
Adding vanilla is optional.
If you like more peanut butter, and less cereal crunch, reduce the amount of cereal to 1 ½ cups. Keep in mind the “dough” will be stickier if you do this.
If you don’t own a small cookie scoop, you can roll the balls with your hands. If you find the “dough” is super sticky, lightly wet the palms of your hands before rolling.
If you don’t own or want to use a microwave, follow the same directions using a large pot on the stovetop.
Finishing the peanut butter balls with a drizzle of melted white chocolate is optional but very pretty.
Substitutions
You can use smooth peanut butter, crunchy peanut butter, or a mix of both.
I haven’t tested these with dairy-free butter, but I think it would work just fine.
You can use name brand or off-brand crispy rice cereal.
I use semi-sweet chocolate, but milk, dark, or even white chocolate will work.
If you don’t have or don’t want to use paraffin wax, substitute an equal amount of butter, shortening, or coconut oil. Fat will help keep the chocolate glossy, but it won’t keep it as solid at room temperature as paraffin wax will.