Peel potatoes and cut into 1 1/2-in. cubes. Put in a large bowl, cover with cold water, and refrigerate overnight.*
Preheat oven to 475°. Bring a large pot of lightly salted water to a boil over high heat. Add potatoes and cook until barely tender when pierced, about 10 minutes. Pour into a colander and let drain and dry 10 minutes.
Set potatoes in a single layer in a large rimmed baking pan. Drizzle evenly with olive oil and sprinkle with 1/2 tbsp. salt; stir gently to coat.
Bake potatoes until golden brown, 25 to 30 minutes, turning halfway through baking. Mound hot potatoes on a platter or in a shallow serving bowl; sprinkle with more salt to taste.
*Soaking the potatoes at least a day (and up to 2 days) ahead makes them even crisper on the outside and creamier in the middle.
Note: Nutritional analysis is per serving.