Spray a rimmed baking sheet generously with nonstick cooking spray. Cut larger potatoes into 1- or 1-½ inch chunks (bigger chunks=more creamy insides, smaller chunks=more crispy outsides), and cut baby potatoes in half. Spread them out on the baking sheet, drizzle the olive oil over, sprinkle the salt over, and toss with your hands to combine.
Make sure they are in a single layer and roast for 40 to 50 minutes or so, tossing them once towards the end of cooking and spreading them out again. If they are sticking to the baking sheet, just leave them be! After a little more time in the oven, they will crisp up on the bottom and be easier to flip.
Add a sprinkle of additional salt if needed, and serve, but warn people that they are HOT.
Notes
You can use whole waxy red or white or Yukon gold potatoes and cut them into 1-inch chunks, or use baby potatoes, as I did here, and cut them in half.
No need to peel the potatoes! The skin adds even more crispiness to the exterior.
Mix the potatoes with the oil and salt right on the baking sheet, sprayed first with nonstick spray, which saves washing a bowl.
If you cut the potatoes into bigger chunks (2 to 3 inches), you'll have creamier insides. Smaller chunks (1 to 1 ½ inches) result in crispier outsides. There's no wrong way to go! But keep the potatoes of a similar size so they cook evenly.
If you are roasting more potatoes than can be spread out in a single layer, then use two baking sheets, and rotate them halfway during cooking so that each tray has a chance to be on the top and bottom so they brown up evenly.
Don't overcrowd the pan.
You may have to tack on a few extra minutes of cooking time if you are roasting two trays at one time.