Preheat the oven to 350℉. Line a 9x13- inch baking dish with parchment paper and set aside.
In a medium-sized bowl combine the flour, baking powder and salt together and set aside.
In another bowl using an electric mixer beat together the butter and sugar until light and fluffy. Scrape down the bowl and add in the eggs and vanilla, beat until combined.
Slowly add the flour mixture until just combined. Scrape down the sides of the bowl and fold in the crushed potato chips.
Place the dough into a baking dish and press flat with your hands. Bake for 30 minutes until the top is golden brown. Let it cool completely before preparing the topping.
In a microwave-safe bowl add the condensed milk, chocolate chips and butter. Microwave in 30-second increments, stirring in between until the mixture is completely melted.
Pour the fudge topping over the cookie bars and smooth with a spatula. Sprinkle the top with the remaining potato chips.
Place in the fridge long enough for the fudge to harden. Then lift the whole sheet of bars out the pan and cut into squares.