01 - Line an 8-inch square baking pan with parchment paper, leaving an overhang for easy removal.
02 - Combine chocolate chips, sweetened condensed milk, and 2 tablespoons butter in a microwave-safe bowl. Microwave in 30-second intervals, stirring after each, until smooth (about 2 minutes). Stir in ½ teaspoon vanilla extract.
03 - Pour the melted chocolate mixture into the prepared pan, spread evenly, and refrigerate.
04 - In a separate microwave-safe bowl, combine peanut butter and ½ cup butter. Microwave for 1 minute, then stir until smooth. Add powdered sugar, vanilla extract, and salt; mix until creamy and fully combined.
05 - Spread the peanut butter mixture evenly over the chilled chocolate layer.
06 - Refrigerate the pan for at least 2 hours until firm.
07 - Remove fudge from pan using parchment overhang. Cut into 24 squares. Serve chilled or at room temperature.