Place whole heads of garlic in a small heavy saucepan with oil. Cook and stir over medium-low heat for 5 minutes. Cover and reduce heat to low for 15 minutes or until garlic is tender. Remove heads of garlic from oil; drain on paper towels. Cool.
Unroll pizza dough. Roll or stretch dough into a 15x10-inch rectangle; cut into six 5-inch squares. Transfer squares to a lightly greased 15x10x1-inch baking pan. Prick generously with a fork. Bake in a 425 degree F oven for 7 to 8 minutes or until lightly browned.
Spread pesto over hot crusts. Arrange Brie or Camembert cheese slices atop pesto. Divide heads of garlic into cloves and peel. With a small, sharp knife, cut cloves lengthwise in half (small cloves can be left whole). Press garlic pieces into cheese. Bake pizzas for 8 to 10 minutes more or until cheese softens. To serve, cut each pizza square in half diagonally. Makes 12 appetizer servings.