Preheat the oven to 400°F (200°C). Place the tomatoes on a baking sheet, drizzle with olive oil, sprinkle with salt, pepper, dried basil, and oregano. Roast in the oven for 30-40 minutes until caramelized.
In a large pot, heat olive oil over medium heat. Add chopped onions and minced garlic, sauté until fragrant.
Add the roasted tomatoes (along with any juices from the baking sheet) to the pot. Pour in the vegetable broth and bring to a simmer. Cook for 15-20 minutes.
Using an immersion blender, blend the soup until smooth. Stir in the heavy cream and season with salt and pepper to taste. Keep warm over low heat.
In a separate pan, melt butter over medium heat. Add the cubed bread, sprinkle with garlic powder, and toast until golden and crispy, about 5-7 minutes.
Serve the creamy roasted tomato soup hot, topped with garlic croutons. Enjoy!