Steps
1. In a microwave-safe bowl, combine peanut butter, milk powder, sugar, and butter.
2. Microwave the mixture for 30 seconds, then stir until smooth.
3. Add a pinch of salt and mix well. If desired, fold in nuts or chocolate chips.
4. Pour the mixture into a small square dish lined with parchment paper.
5. Spread it evenly and refrigerate for about 30 minutes or until firm.
6. Once set, cut into small squares and enjoy!