Place garlic heads in a baking dish and drizzle each with 1 tablespoon of olive oil. Bake in the preheated oven until garlic is soft and brown, about 45 minutes.
Bring a large pot of water to a boil and stir in sea salt. Cook potatoes in the salted water until tender, about 30 minutes. Drain.
Transfer potatoes to a large bowl and add sour cream, cream cheese, butter, salt, and black pepper to the bowl. Cover bowl with a lid or a piece of aluminum foil and let mixture stand for 5 minutes to soften butter and cream cheese, about 5 minutes.
Squeeze roasted garlic from the cloves into the potato mixture; mash potatoes until smooth, creamy, and thoroughly combined.