Chocolate Peanut Butter Meltaways

One 12-ounce jar crunchy peanut butter
5 tablespoons (½ stick plus 1 tablespoon) unsalted butter, at room temperature, plus more if needed
2 cups confectioners’ sugar, sifted
1½ cups crispy rice cereal
11 ounces bittersweet or semisweet chocolate, finely chopped
1 tablespoon vegetable shortening

Bringing the temperature of the chocolate up to about 115°F and then cooling it to about 90°F helps it to set better.

Line a baking sheet with aluminum foil. In a medium bowl, using a wooden spoon, cream the peanut butter with the butter until combined. Gradually stir in the confectioners’ sugar. Stir in the cereal, which will crumble. (The moisture in the peanut butter varies from brand to brand—if the peanut butter mixture seems too crumbly, mix in more softened butter until it is malleable.) Using about 1 tablespoon for each, roll the mixture into balls, placing them on the prepared baking sheet. Refrigerate the balls while melting the chocolate.
In the top part of a double boiler placed over hot, not simmering, water, melt the chocolate with the shortening, stirring occasionally until smooth and an instant-read thermometer inserted in the chocolate reads 115°F to 120°F. Remove from the heat. Transfer the chocolate mixture to a small bowl and let cool to 88°F to 90°F, stirring occasionally.
Place a dab of the chocolate in the palm of one hand. Pick up a peanut-butter ball and roll it between your palms to coat lightly with the chocolate. Return the chocolatecoated ball to the foil-lined baking sheet. Repeat with the remaining balls. Refrigerate until the chocolate is set and the balls release easily from the foil, about 30 minutes.