01 - Line an 8-inch square baking pan with parchment paper and lightly grease with butter.
02 - In a medium saucepan over low heat, melt the peanut butter and butter together, stirring until smooth. Remove from heat.
03 - Stir in the vanilla extract and salt. Gradually add the powdered sugar, mixing until fully combined and smooth.
04 - Spread the peanut butter mixture evenly into the prepared pan and smooth the top.
05 - In a small saucepan, heat 1/2 cup heavy cream over medium heat until just simmering. Remove from heat and add 1 cup chocolate chips, stirring until melted and glossy.
06 - Pour the chocolate layer over the peanut butter base and spread evenly.
07 - Refrigerate for at least 2 hours, or until fully set.
08 - Lift the fudge from the pan using the parchment, cut into squares, and serve.