Spray medium saucepan with nonstick spray; heat. Add garlic; cook over medium heat, stirring constantly, until lightly browned, 1-2 minutes.
Add crushed tomatoes, tomato sauce, oregano, and basil; stir to combine. Bring to a boil; reduce heat. Let simmer until thickened and flavors are blended, about 15 minutes.
Stir in sweetener; let cook 5 minutes longer.