Melt the butter and peanut butter in a saucepan over medium-low heat until creamy.
Slowly add the powdered sugar to the peanut butter mixture until it forms a pliable mass.
Remove from heat and wrap the peanut butter mixture in plastic wrap, then refrigerate for about an hour.
Fill a mold about halfway with melted chocolate.
Pinch off small pieces of the peanut butter mixture and roll them into small balls, then flatten them slightly into disks.
Press a peanut butter disk into each half-filled mold, then cover with more melted chocolate. Tap the mold gently on the table to release any air bubbles.