Preheat oven to 350F.
Cut the tops off each head of garlic.
Place each head of garlic into a cup on the muffin tin. If you're only roasting one or two, wrap each head in a small piece of foil individually.
Drizzle the tops of garlic head with olive oil.
Cover the muffin tin completely with foil.
Bake in oven for 45 minutes. Remove from oven and set somewhere to cool.
Once the garlic is cool enough to handle, squeeze the softened garlic cloves out.
Mix equal parts of roasted garlic with butter to spread on bread, add to mashed potatoes, roast a chicken, or anywhere else you could use roasted garlic.