Line a baking sheet with parchment paper and line with pretzels.
Beat peanut butter and butter until combined. Add sugars and beat until combined. (You should be able to roll the mixture into balls without it sticking to your hands. If it's sticky, add more powdered sugar until the consistency is easy to roll.)
Roll mixture into small balls and place balls on the pretzels. Press additional pretzels onto the balls, sandwiching the mixture.
Melt the chocolate. Dip each pretzel bite halfway into the melted chocolate and place onto lined baking sheet.
Chill in refrigerator until the chocolate is firm.