Preheat oven to 450°.
Cook beef, onion, and carrot in a large nonstick skillet over medium-high heat until browned, stirring to crumble. Drain well; return meat mixture to pan. Stir in barbecue sauce, sugar, salt, and pepper; reduce heat, and simmer 5 minutes.
Place pizza crusts on a baking sheet. Divide beef mixture evenly among crusts, and sprinkle with cheese. Bake pizzas at 450° for 12 minutes or until cheese melts. Sprinkle pizzas with cilantro. Cut each pizza into 4 wedges.
I served these as an appetizer when my young nieces were over. Adults and kids loved them. Great recipe.