Preheat oven to 425°.
Cook burger crumbles and onion in a large nonstick skillet over medium-high heat 6 minutes or until crumbles are thoroughly heated. Add tomatoes and seasoning; cook 1 minute, stirring frequently.
Unroll pizza crust dough. Press into bottom and halfway up sides of a 13 x 9-inch baking dish coated with cooking spray. Spoon burger mixture over pizza crust dough.
Bake at 425° for 10 minutes. Top with cheese, and bake 3 to 4 minutes or until cheese melts and edges of crust are browned. Let stand 5 minutes before slicing. Top with salsa and sour cream.