Line a large baking sheet with parchment paper or a silicone baking mat. Set aside. Make sure you have enough room in your freezer for the baking sheet or use the refrigerator in step 3.

Using a handheld or stand mixer fitted with a paddle attachment, beat the peanut butter and butter together on medium speed. If you don’t have a mixer, just use a spoon and some arm muscle. Stir or beat in confectioners’ sugar and brown sugar until a thick dough forms.

Roll peanut butter dough into 30 small balls. Mixture can be sticky, so do your best. If it seems impossibly sticky, mix in 1/4 cup (30g) confectioners’ sugar.

Sandwich peanut butter balls between two pretzels and place on prepared baking sheet. Freeze for 20–30 minutes, or refrigerate for 1 hour.

While the pretzel bites are chilling, melt chopped chocolate in a double boiler or in 20-second increments in the microwave, stopping and stirring after each increment until smooth. Dip the pretzel bites halfway into the melted chocolate and place bite back on baking sheet. Refrigerate pretzel bites for at least 10–20 minutes to set the chocolate.

Cover and store pretzel bites in the refrigerator for up to 10 days. Bites can be frozen for up to 3 months. Thaw overnight in the refrigerator.