Cut top off garlic head. Place garlic on a piece of aluminum foil; drizzle with olive oil. Fold edges together to seal. Bake 30 minutes; cool.
Squeeze cooked garlic into a medium bowl. Garlic will be soft and sticky. Add butter, parsley salt and pepper, stirring to combine.
Spread cut halves of bread evenly with garlic butter mixture. Broil 5 1/2 inches from heat, with oven door partially opened, for 2 to 3 minutes, or until butter melts and bread is toasted. Cut into slices to serve.