Step 1

Coat a 9- x 13-inch baking dish with cooking spray.

Step 2

In a medium saucepan over medium heat, combine butter, evaporated milk, and sugar; cook until mixture comes to a boil, stirring constantly. Boil 5 minutes, then remove from heat.

Step 3

Stir in peanut butter, marshmallow cream, and vanilla until thoroughly combined. Pour mixture into baking dish and spread evenly. Cool and refrigerate for 8 hours or until firm.

Step 4

Cut into 1-inch squares. Store in an airtight container.