Pre-heat the oven to 425°F. Line two baking sheets with parchment paper and place a wire rack on top. Spray the rack with nonstick spray.
Add ground beef to a large bowl and season with salt and pepper, then let sit at room temperature while you work on the fries. Preheat the grill to medium-high heat.
Cut each potato into very thin fries, lengthwise no more than a quarter-inch thick. In a large bowl, toss the fries with olive oil. I think I used about 2 tablespoons. Add the seasoned salt and pepper and arrange the fries in single layer without crowding them on the wire racks (this is very important - I used two baking sheets).
Bake for 20 minutes, remove and toss, then bake for 15-20 minutes longer. I like to start checking them at 15 minutes and make sure none are burning or getting too crisp.
About 15 to 20 minutes before the fries are ready form the beef into 4 equal patties and grill (or you can fry them in a skillet as well) until they reach their desired doneness. I cook mine about 4 minutes per side, but it will depend on how thick you like your burgers. In the last 1-2 minutes of cooking, top each burger with a few slices of cheddar cheese if desired (I do not do this for our peanut burgers, but some people love it!). Remove from the grill and cover with foill to keep warm while you make the milkshakes.
In a blender, combine the ice cream, malted milk powder and vanilla. Add the milk, a quarter cup at a time, blending between each addition, until the desired consistency is reached. Divide between four glasses and top with generous amounts of whipped cream and hot fudge sauce.
To assemble burgers warm the peanut butter in the microwave for 30 seconds. Place the burger on its bun and spread a generous amount of the warmed peanut butter on top of the burger. Top with 2 slices of bacon if desired and add the burger bun.
Serve the burgers with a side of slim jim fries and the milkshakes! Dig in!