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.
Place dough in a large bowl coated with cooking spray, turning dough to coat. Cover; let rise in a warm place (85°), free from drafts, 1 hour or until doubled in size. (Press two fingers into dough. If indentation remains, dough has risen enough.)
Punch dough down; cover and let rest 5 minutes. Roll dough into a 14-inch circle on a lightly floured surface. 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.
Preheat oven to 450°.
To prepare topping, cook bacon in a large nonstick skillet over medium heat until crisp. Remove bacon from skillet, reserving 2 teaspoons of bacon drippings in pan. Crumble bacon; set aside. Add onion and mushrooms to pan; cook 10 minutes or until tender and moisture evaporates, stirring occasionally. Remove from heat; sprinkle with 1/4 teaspoon salt and 1/8 teaspoon pepper.
Drizzle oil over dough; sprinkle with remaining 1/4 teaspoon salt and 1/8 teaspoon pepper. Place pan on lowest oven rack; bake at 450° for 10 minutes or until golden-brown. 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. Bake an additional 10 minutes or until crust is lightly browned. Let stand 5 minutes before serving. Cut into wedges.