Line a 9" x 5" loaf pan or a 8" x 8" cake pan with parchment paper. Heat all ingredients in a small saucepan over medium-low heat. Stir constantly and heat just until all ingredients are melted and well combined together in a creamy substance. Pour the peanut butter fudge mixture into the prepared pan and smooth into an even layer. If desired, sprinkle with coarse sea salt. Freeze for at least 2 hours, or until fudge is firm and set up. Remove from freezer and lift the fudge out of the pan by tugging on the parchment paper. Transfer to a cutting board. Cut into squares, serve, and enjoy! Store leftovers in a zip lock bag in the freezer.
