Butter the inside of glass baking dish or line with parchment paper and butter paper.

Mix Sugar, Corn Syrup and Evaporated milk in large pan and cook over medium heat. Sir occasionally. Mixture will begin boiling. If it boils too close to top reduce heat slightly.

Continue cooking until mixture reaches soft ball stage (235-245 degrees). You can test for this by seeing the syrup forms a ball while in the cold water, but flattens once removed from the water.

Remove from heat and add butter and vanilla.

Stir until butter is melted and incorporated.

Add peanut butter and continue stirring until mixture start to lose its' sheen. Then pour into prepared dish and allow to cool.