Preheat oven to 350 degrees F.
Line a large rimmed baking sheet (around 17x12 inches) with nonstick foil.
Put 2 cups of broken pretzels (or minis) onto the rimmed baking sheet, then add 2 cups of Fritos -- you can leave them whole or break them up. Throw in the peanuts.
Unwrap peanut butter cups, but don't throw them in quite yet.
Place butter in a large non-stick saucepan and melt over medium heat. When butter is melted, stir in brown sugar. Bring mixture to a full boil and boil for 1 minute, stirring once or twice.
Working quickly, drizzle hot sugar mixture over Frito mixture, stirring a little to coat the Fritos and Pretzels. Immediately place in the oven and bake for 8 minutes.
After 8 minutes, pull from oven and sprinkle on the unwrapped peanut butter cups. If you want, you can also throw in some Reese's candies or chocolate chips.
Allow the mixture to cool slightly.
Put the chopped chocolate (or chips) in a large microwave-safe bowl and heat on high for 30 seconds. Stir and repeat until chocolate is melted and smooth. Drizzle the melted chocolate over the candy. Allow it to set at room temperature or let it cool somewhat and then transfer to the freezer to quick set it.
When chocolate is set, lift from pan and break the candy up as you would almond toffee. You can eat it cold or let it come back down to room temp.