Prepare crust by combining pizza crust mix and hot water in large bowl. Stir until moistened; cover and let stand 10 minutes in a warm place.
Remove dough from bowl and knead on floured work surface until dough is smooth and springs back when touched. Roll dough into 8x8-inch square, about 1/4-inch thick; set aside.
Preheat oven to 425°F. Spray 8x8-inch glass baking dish with cooking spray; set aside. Heat large skillet over medium-high heat. When hot, add beef and onion; cook 5 to 7 minutes or until meat is crumbled and no longer pink. Drain fat. Add flour and pepper; stir until well blended.
Add undrained tomatoes, ketchup, pickles and mustard to meat mixture; stir to combine. Place in prepared dish. Sprinkle meat mixture with cheese; top with pizza crust dough.
Lightly spray dough with cooking spray; sprinkle with sesame seeds, if desired. Bake 18 to 22 minutes or until crust is golden brown.