Preheat the oven to 400 degrees F. Slice off the head of the garlic and sprinkle it with a little olive oil and salt. Wrap and cover it with tinfoil and roast in the oven, cut side up, for 45 minutes. Remove from the foil and let it cool. Squeeze the cloves out, mash and chop. Set aside. Lower the oven temperature to 350 degrees F. Slice the baguettes into 24 pieces and lightly brush them with olive oil. Bake in the oven for 10 to 12 minutes or until lightly toasted. Remove them from the oven and set aside. Meanwhile, coarsely chop the heirloom tomatoes and add them to a large mixing bowl. Add the olive oil, minced garlic, fresh basil, salt and pepper and mix until well combined. In a small mixing bowl, add the crème fraiche, mashed roasted garlic and lemon zest. Mix until well combined and sprinkle with salt and pepper. Spread a small amount of roasted garlic crème fraiche onto each toasted baguette piece. Using a slotted spoon (or clean hands!), top each piece with the heirloom tomato mixture.