Heat oven to 400°F. Lightly grease 12-inch pizza pan or pizza stone with shortening or spray with cooking spray. Unroll dough; place on greased pan. Starting at center, press out dough to edge of pan.
Lightly spray dough with olive oil cooking spray. Sprinkle Asiago cheese and garlic salt over dough. Bake at 400°F. for 8 to 10 minutes or until lightly browned.
Remove partially baked crust from oven. Spread ranch dressing over crust. Top with chicken, bell pepper, onion and spinach. Sprinkle Italian cheese blend and pizza seasoning over top.
Return to oven; bake an additional 9 to 12 minutes or until cheese is melted and pizza is thoroughly heated. Cut into wedges.