Heat the olive oil in a large Dutch oven over medium heat until it shimmers. Add the onion, garlic, bay leaf, and red pepper flakes and cook until the onion is softened and translucent, about 5 to 7 minutes.

Stir in the tomatoes with their juice, bread pieces, brown sugar, broth, and brandy. Bring the mixture to a simmer and cook for 5 minutes, using a wooden spoon to break the tomatoes into smaller pieces as they soften.

Remove and discard the bay leaf. Transfer the soup to a blender and process until completely smooth; work in batches and fill the blender jar no more than halfway to prevent the hot liquid from overflowing.

Return the soup to the pot and warm through over medium-low heat. For an exceptionally silky finish, pass the pureed soup through a fine-mesh strainer before reheating.

Season with salt and pepper to taste. Serve hot, finished with a drizzle of olive oil and a sprinkle of chives.