Melt the Chocolate: In a microwave-safe bowl, melt 2 cups of milk chocolate chips in 30-second intervals, stirring between each, until smooth (about 1–2 minutes). Avoid overheating to prevent burning.
Prepare the Filling: Let the melted chocolate cool slightly, then beat in the Cool Whip using a hand or stand mixer until light and fluffy.
Set the Filling: Line an 8x8-inch baking dish with parchment paper. Spread the mixture evenly and freeze for 30–40 minutes until firm but not frozen solid.
Cut into Squares: Lift the chilled filling from the pan, place it on a cutting board, and cut it into small squares or bars.
Coat the Bars: Melt the remaining 4 cups of chocolate chips with vegetable shortening in the microwave, stirring every 30 seconds until smooth. Dip each square in the melted chocolate, letting the excess drip off before placing them on a parchment-lined tray.
Chill: Refrigerate for 20 minutes until the chocolate coating hardens.