Melt butter in a large Dutch oven over medium heat; add garlic, and saute' 1 minute or until slightly golden. Stir in tomatoes and next 4 ingredients; cook, stirring occasionally, over medium heat 30 minutes. Remove from heat, and let cool 10 minutes.
Process mixture, in small batches, in a blender or food processor until smooth, stopping to scrape down sides. Return mixture to Dutch oven.
Stir in Half and half, and cook, stirring occasionally over low heat 8-9 mins or until thoroughly heated; stir in red and black pepper. Add basil if desired.