Coarsely chop tomatoes. They can be pureed in a blender or food processor for a more "saucy" texture, or thrown in the pan as is for chunky-style. Add water in very small quantities while pureeing until the desired texture is achieved.
In a medium saucepan, heat olive oil to medium heat. Add garlic and bay leaf. Saute briefly (1-2 minutes), but take care not to brown the garlic.
Add tomato sauce, basil, pepper flakes, salt, pepper, and brown sugar.
Reduce heat to simmer. Cover and cook for at least 1/2 hour, stirring occasionally.
This recipe can be altered with great results. My brother adds onion and roasted bell pepper. My mom uses canned tomatoes, and also uses other herbs like thyme and oregano. You can also use more or less of the ingredients listed, as suits your taste buds (of course).
Be creative, and enjoy!