When oven reaches 200° F., turn it off. Lightly grease a large bowl with vegetable cooking spray. Coat each of two 9" cake pans with 3 T. olive oil.
Dissolve yeast in lukewarm skim milk. Combine 1 T. olive oil and sugar and with yeast mixture. Put flour and salt in food processor with metal blade. Add yeast mixture, and process until a smooth ball is formed. Put in greased bowl, and let rise in the previously warmed oven, covered, for 1/2 hour.
When the dough has doubled in size, transfer it to a lightly floured surface, divide in half, and light roll each half into a ball. Working with 1 dough ball at a time, roll and shape the dough into 9 1/2 inch rounds, and press into the oiled pans. Cover with plastic wrap and set in a warm spot (not in the oven) to rise for about 20 minutes. Meanwhile, preheat the oven to 400° F.
Remove plastic wrap from dough. Put half of the sauce on each round, leaving 1/2 inch border around edges. Put half of the topping on each pizza. Put half of the cheese on each pizza. Bake until cheese is melted and browned, about 20-25 minutes. Remove from oven, and let rest for 1-2 minutes. Using a spatula, transfer pizzas immediately (to keep the crust crisp) to a cutting board, and cut into 6 wedges each.
These pizzas freeze very well -- cool completely, and wrap in foil, storing in freezer bags.