Fill a large bowl with 3-4 cups of ice. Open your hot oven and place the baking sheet with the baguettes inside. (Alternately, you can use a baking stone. Have the stone in the oven preheating. Put the loaves on parchment paper and use the baking sheet to transfer them from the counter to the hot stone in the oven.) After the bread is in the oven, toss the ice cubes on the bottom of the oven and quickly shut the door. Do NOT open your oven for 15 minutes. Bake until golden brown, about 15-18 minutes.