Put cut Reese's cups in freezer for 30 minutes to harden.
Crush Oreos in food processor and add melted butter.
Press mixture into bottom and partway up sides of springform pan.
Refrigerate at least 30 minutes to firm.
Beat together cream cheese, powdered sugar, vanilla and peanut butter until well mixed.
Fold in whipped topping until uniformly blended.
Fold in half of frozen Reese's.
Pour/spread into pan and refrigerate for at least 4 hours or until firm.
Remove from springform pan and top with remaining Reese's.
You can also drizzle with chocolate syrup if desired.