1. To prepare dough: dissolve yeast and sugar in 1/2 cup warm water in a large bowl; let stand 5 minutes. Lightly spoon flour into dry measuring cups, and level with a knife. Stir 1 1/4 cups flour and 1/4 teaspoon salt into yeast mixture 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 flour, 1 Tablespoon at a time, to prevent dough from sticking to hands.
2. Place dough in a large bowl coated with cooking spray, turning dough to coat. Cover; let rise in a warm place (85°F), free from drafts, 1 hour or until doubled in size. (Press two fingers into dough. If indentation remains, dough has risen enough).
3. Punch dough down; cover and let rest 5 minutes.
4. Roll dough into a 14-inch circle on a lightly floured surface.
5. Place dough on a pizza pan or baking sheet coated with cooking spray and sprinkled with cornmeal. Crimp edges of dough with fingers to form a rim.
6. Preheat oven to 450°F.
7. To prepare topping: Cook bacon in a large nonstick skillet over medium heat until crisp.
8. Remove bacon from skillet, reserving 2 teaspoons bacon drippings in pan. Crumble bacon; set aside.
9. Add onion and mushrooms to pan; cook 10 minutes or until tender and moisture evaporates, stirring occasionally.
10. Remove from heat; sprinkle with 1/4 teaspoon salt and 1/8 teaspoon pepper.
11. Drizzle oil over dough; sprinkle with remaining 1/4 teaspoon salt and 1/8 teaspoon pepper.
12. Place pan on lowest oven rack; bake at 450°F. for 10 minutes or until golden brown.
13. Remove from oven; spread ricotta evenly over crust, leaving a 1/2-inch rim. Arrange onion mixture and arugula evenly over ricotta. Sprinkle with bacon, mozzarella, and Parmesan.
14. Bake an additional 10 to 15 minutes or until crust is lightly browned and topping is bubbling.
15. Let stand 5 minutes before serving.
16. Cut into wedges.