1. Dissolve sugar and yeast in 1 cup warm water in a large bowl; let stand 5 minutes.
2. Weigh or lightly spoon 12.4 ounces flour (about 2 3/4 cups) into dry measuring cups; level with a knife. Combine 9 ounces flour (about 2 cups), cornmeal, and salt in a bowl. Stir oil into yeast mixture; stir in flour mixture. Add remaining 3.4 ounces flour (about 3/4 cup) to form a soft dough. Turn dough out onto a lightly floured surface. Knead until smooth and elastic (about 5 minutes); add enough of remaining 2 tablespoons flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel sticky).
3. Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 45 minutes or until doubled in size. (Gently press two fingers into dough. If indentation remains, dough has risen enough.)
4. Preheat oven to 400°.
5. Punch dough down; cover and let rest 5 minutes. Roll dough into an 11 x 15inch rectangle on a lightly floured surface. Place dough in a 13 x 9inch glass or ceramic baking dish coated with cooking spray; press dough up sides of dish. Bake at 400° for 10 minutes.
6. While crust bakes, chop tomatoes; place in a sieve. Drain tomato mixture 10 minutes. Pat tomatoes dry with paper towels. Place tomatoes in a large bowl; stir in oregano and basil.
7. While tomatoes drain, heat a large nonstick skillet over medium heat. Coat pan with cooking spray. Add mushrooms to pan; cook 5 minutes without stirring. Stir in bell peppers; cook 5 minutes or until tender, stirring often.
8. Spread 1 1/2 cups cheese over dough, pressing gently. Arrange chopped sausage evenly over cheese. Arrange vegetables over sausage; spoon tomato mixture evenly over vegetables and sausage. Sprinkle evenly with remaining 1/2 cup cheese.
9. Bake at 400° for 25 minutes or until crust browns and cheese is golden. Cool 5 minutes before cutting.
Young Chefs can:
Measure mushrooms and chopped bell peppers
Older Chefs can:
Chop sausage with dinner knife
Help press dough into baking dish