Step 1

Add the butter to a medium saucepan on medium high heat.

Step 2

Add the evaporated milk and sugar and stir together.

Step 3

Bring the ingredients to a full, rolling boil for four minutes, or until thermometer reaches 234-degrees. Stir often while boiling.

Step 4

Remove from heat and add marshmallow creme. Stir until all of the lumps are gone.

Step 5

Add the vanilla and peanut butter and stir until well blended.

Step 6

Pour into a greased 9" x 9" casserole dish, or a up to a 13" x 9" casserole dish.

Step 7

Cool for at least three hours.