coat 9 inch pan with cooking spray

In a large microwave bowl combine the peanut butter and butter. Microwave @ 80% power for 2 minutes

Remove from microwave and add powered sugar, vanilla, and milk.

Mix well and press into a pie pan

Microwave on 80% power for 1 minute.

Chill in fridge for 1 to 2 hours and cut into 8 wedges