1Combine graham crackers with butter and press into greased pie dish. Freeze for 10 minutes.
2Beat peanut butter, cream cheese, yogurt and sugar together until combined.
3Pour and spread filling into crust. Chill for 1 hour.
4Melt chocolate and butter in a double boiler (glass or metal bowl over boiling pan of water). Once melted, remove from heat and allow to cool for 3 minutes. Continue to stir frequently as it cools. Pour and spread over chilled pie. Chill for 1 to 2 hours or until firm.