MELT chocolate over a double boiler until completely dissolved or by heating on a microwave-safe bowl, in intervals of 15 seconds, until chocolate is completely melted.
POUR light corn syrup over chocolate and mix with a rubber spatula until chocolate thickens and looks slightly grainy. Don't overstir.
POUR mixture over plastic wrap and cover tightly. Let REST overnight or refrigerate for 4 hours, until modeling chocolate has hardened.
CUT into 4 equal parts and KNEAD each part separately until it softens. Chocolate will feel quite hard; continue kneading until warmth of your hands softens chocolate. Chocolate must be pliable and hold its shape.
KNEAD all pieces together and add peanut butter.
KNEAD until well combined.
