Parmesan-Crusted Smashed Potatoes

Preheat oven to 400°F. Cut 1/2 inch off top of garlic head to expose cloves. Place garlic head, cut side up, on a small sheet of aluminum foil, and drizzle with 1 teaspoon of the oil. Bring edges of foil together over garlic and crimp edges to seal. Place foil packet directly on oven rack in preheated oven, and roast until garlic cloves are tender and creamy, 35 to 40 minutes. Carefully open garlic packet and let cool for 15 minutes. Squeeze garlic cloves out of skins into a small bowl. Mash garlic with a spoon until smooth; set aside. Increase oven temperature to 425°F.

While garlic roasts, place water, potatoes, salt, baking soda, and bay leaves in a large saucepan. Bring to a boil over high. Reduce heat to medium-high and gently boil until potatoes are just easily pierced with a paring knife, 12 to 15 minutes. Drain potatoes; let cool 5 minutes. Discard bay leaves.

Transfer potatoes to a large rimmed baking sheet lined with parchment paper. Using flat bottom of a measuring cup, smash each potato to about 1/2-inch thickness, keeping potatoes intact and spacing them about 1/2 inch apart for maximum browning on all sides. Mix rosemary, 1/2 cup of the grated cheese, and remaining 6 tablespoons oil into mashed garlic in bowl. Spoon about 1/4 cup garlic-cheese mixture evenly onto potatoes; sprinkle evenly with 2 tablespoons of the grated cheese. Season with salt and pepper to taste. Flip potatoes over. Spoon remaining garlic-cheese mixture evenly onto potatoes, and sprinkle evenly with remaining 2 tablespoons grated cheese. Season with salt and pepper to taste. Roast at 425°F until cheese is browned, 40 to 45 minutes, flipping potatoes halfway through cook time. Remove from oven; let cool 10 minutes. The coating will crisp as it cools.