Preheat oven to 425°. Place potatoes in a 3-quart saucepan and cover with cold water. Add salt to taste and bring to a boil over high heat. Boil for about 7 minutes or until fork-tender. Drain thoroughly and place in a large bowl.
In a small bowl, mix the Hellmann’s® Mayonnaise Dressing with the sriracha until combined.
Toss 2/3 of the spicy mayonnaise mixture with the hot drained potatoes until evenly coated. Place potatoes on a lined sheet pan and smash each potato to ½-inch thickness with a flat-bottomed glass, using a small offset metal spatula to help release from glass, if needed. Spread smashed potatoes in a single layer and brush with remaining mayonnaise mixture.
Bake 30 minutes, flipping halfway through bake time. Sprinkle with salt to taste and serve.