Dissolve the yeast in the warm water in a large mixing bowl and set aside for 15 minutes.
Stir in the eggs and oil. Combine 3 cups of the flour with the salt and pepper, and stir into the yeast mixture. Knead to combine adding more flour, a little at a time, to make a firm dough.
Combine the parmesan cheese and the prosciutto and lightly dust with flour. Work the misture into the dough. Turn the dough out onto a floured board and knead until smooth, 10 minutes. Return the dough to a well-oiled bowl, cover, and set aside to rise in a warm place until doubled in size, about 2 hours.
Punch down the dough and knead for 3 minutes. Divide the dough in half. Form each half into a oblong loaf. Sprinkle 2 baking sheets with cornmeal and place a loaf on each. Set aside to rise until doubled in size, about 1 hour.
Line the oven with wet baking tiles, stones or trays of terra-cotta chips and preheat to 425F.
Using a razor, make 6 slashes diagonally across the top of each loaf. Bake until golden, about 40 minutes, spraying with a plant mister every 5 minutes for the first 15 minutes of baking. Cool on a wire rack.
Makes 2 loaves.
Source: New York Cookbook, Molly O'Neill, 1993
From: D&G Bakery, Spring Street, Manhatten