Line a 9-inch square cake pan with parchment paper, making sure to leave an overhang of paper.
Combine the SunButter and butter in a medium saucepan and melt over medium heat, stirring until the SunButter is melted and the mixture is fully combined.
Remove from the heat and add the vanilla, powdered sugar, and salt. Stir well. The mixture will be like very thick cookie dough.
While still warm, stir in the chocolate chips. Stir until mostly combined with a few streaks. Press the mixture evenly into the prepared pan, cover, and chill for 4 hours.
Using the parchment paper to help you, lift the fudge from the pan and cut into small squares. Can be stored, covered, in the refrigerator.