For the sponge: Sprinkle yeast over warm water in a large mixing bowl. Whisk it in and let stand until creamy, about 10 minutes. Stir in flour. Cover tightly with plastic wrap and let stand until bubbly and doubled in volume, about 45 minutes. For the dough, sprinkle yeast over warm water. Let stand until creamy, about 5-10 minutes. With a wooden spoon, stir the yeast mixture and the olive oil into the sponge and mix well. Stir in 1 c of the flour and the salT Stir in enough remaining flour to produce a soft dough. Knead on a lightly floured board until soft and smooth, about 6-8 minutes. Place dough in a lighly oiled bowl, cover with plastic wrap and let rise until doubled 1 to 1 14/ hrs or overnight in the fridge. Divide dough in half and press into two lightly oiled 23 cm round cake pans. If dough shrinks from the sides, let rest a few minutes then stretch it again. Cover with a towel and let rise in a warm place for 45 minutes or until dough is full of air bubbles. Just before baking, press your fingertips deep into the dough all over the surface to dimple the loaf. Drizzle with olive oil and sprinkle with sea salT Bake at 425 deg. for 20-25 minutes until top is golden. Remove from pan and cool on a wire rack.
----