Preheat oven to 450 degrees. Cover potatoes with water by 2 inches in a medium pot. Bring to a boil, season with salt, and reduce heat to a rapid simmer. Cook until potatoes are tender when pierced with a fork, about 20 minutes; drain. Gently smash each potato until slightly flattened but still in one piece (edges will split).
Brush a rimmed baking sheet with 1 tablespoon oil. Place potatoes on sheet in a single layer and brush tops with remaining 1 tablespoon oil. Bake until golden brown and crisp, flipping once, about 25 minutes. Remove from oven, season with salt, and serve.