Line a baking sheet or large plate with wax paper or parchment paper.
Spread the peanut butter evenly over 12 Ritz crackers. Top with the remaining crackers to make 12 sandwich cookies.
Melt the milk chocolate in a microwave-safe bowl in 30-second intervals, stirring after each, until smooth. You can also melt the chocolate in a double boiler.
Using a fork, dip each peanut butter cracker sandwich into the melted chocolate, coating it completely. Let the excess chocolate drip off.
Place the coated crackers on the prepared baking sheet.
Let the chocolate set completely at room temperature, or refrigerate for 15 to 20 minutes to speed up the process.
Store the crackers in an airtight container at room temperature or in the refrigerator until ready to serve.
Notes
Store the leftovers in an airtight container or ziplock bag at room temperature for up to 1-2 weeks.