Combine graham crackers with butter and press into greased pie dish. Freeze for 10 minutes.
Beat peanut butter, cream cheese, yogurt and sugar together until combined.
Pour and spread filling into crust. Chill for 1 hour.
Melt 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.