Mix yeast and sugar and dissolve in warm water. Let stand for about 5 minutes. Add in salt, oil and oat bran, if desired.
Mix in 4 1/2 cups of flour. Then continue to add additional flour (up to 6 cups) and knead until dough is smooth and elastic (I use my Kitchenaid with the dough hook attached--dough should clean the side of the bowl).
Place into a greased bowl, turning once, cover and allow to rise until dough is doubled in bulk.
Prepare 2 large (14 inch or larger) pizza pans by coating them with cooking spray and sprinkling lightly with cornmeal.
Punch down and roll dough to fit 2 large pizza pans.
Top as desired.
For a crust that is crispy on the bottom, place pizza on the bottom rack in a cold oven, set the oven for 500° and bake for about 20 minutes or if the oven is already hot, bake at 500° for 10-15 minutes (watch closely).