Beat peanut butter, butter & vanilla until combined.
Graually beat in powdered sugar.Spread mixture on cake. Refrigerate for 30 minutes.
Make Ganache: Heat cream in small saucepan to boiling. REmove from heat. Add chocolate chips and whisk until melted and smooth. Let stand for 5 minutes.
Spread chocolate on top and sides of cake.
Make Drizzle: Melt chocolate peanut butter chips in microwave for 30 seconds, stir, if needed microwave in 10 second intervals until melted. Spoon into a small baggie and cut a small corner. Drizzle over cake