Line a 9-by-13-inch baking dish with parchment leaving a 2-inch overhang on 2 of the sides.
Bring the milk to a boil in a medium saucepan over medium-high heat. Immediately remove from the heat and add 1 of the bags of chips. Stir gently to make sure all the chips are covered with milk. Let sit until the milk is bright orange and the chips are no longer coated with the cheese powder, about 2 minutes. Strain the milk and return it to the saucepan (you should have 2 1/2 cups of milk). Discard the wet chips.
Add the macaroni to the steeped milk and bring it to a boil over medium heat. Cook, stirring frequently to keep the macaroni from clumping, until the macaroni is tender and the milk has thickened to the consistency of heavy cream, 4 to 5 minutes.
Remove the saucepan from the heat, add the Cheddar, cream cheese, butter and 1/2 teaspoon salt and stir until smooth, thick and creamy. Spread the macaroni into the prepared baking dish and freeze until firm and stiff, about 1 hour.
Meanwhile, pulse the remaining bag of chips in a food processor until fine crumbs. Put the eggs, flour and chip crumbs into 3 separate shallow dishes. Lightly beat the eggs.
Lift the macaroni slab from the baking dish using the parchment overhangs for handles. Cut the macaroni into 3-inch equilateral triangles. Dredge each triangle in the flour, then dip in the eggs, letting any excess drip off, and finally press into the chip crumbs to cover completely. Put the triangles on a baking sheet and freeze until chilled, about 10 minutes.
Fill a large heavy pot with 2 inches of oil and attach a deep-frying thermometer to the pot. Heat the oil over medium heat to 375 degrees F.
Working in batches, fry the triangles until golden brown on the outside and heated through on the inside, about 3 minutes. Use a slotted spoon to lift the triangles from the oil and transfer to a paper towel-lined plate; let the oil come back to temperature between batches. Season with salt and serve the triangles in a chip bowl with ranch dressing for dipping.
Copyright 2018 Television Food Network, G.P. All rights reserved.