Preheat your oven to 400 degrees F.
Remove any loose papery skin from the garlic but leave the head of garlic intact. Cut about one-half inch off the top of the head of garlic--enough to expose the interior of the garlic cloves. Place the garlic head in the ovenproof dish, cut-side up. Drizzle the oil over the garlic. Cover with foil and bake in a preheated oven for about 30 minutes or until garlic feels soft (pierce with tip of sharp knife to test).
Set aside until cool enough to handle. Squeeze the garlic cloves from the bottom to release the roasted garlic pulp, which should now be sweet, creamy, and golden brown in color. The resulting roasted garlic pulp can be spread on bread, mixed with softened butter, stirred into dips, or added to sauces. The only limit is your imagination.
Cooks Note: A good head of garlic should be plump and firm, with no visible mildew, spoilage, or shriveling and very little if any sprouting (the green sprouts can be bitter).