In a large pot over medium heat, melt the butter with the olive oil. Add the onions and carrots, and cook for about 7-10 minutes, or until softened.
Add salt, pepper, basil, and crushed red pepper. Cook for about 30 seconds just to warm the spices up.
Add in the canned tomatoes and stock. Simmer for 30 minutes.
Stir in the cream, basil, and parmesan cheese. Simmer an additional 5 minutes.
Puree using a blender or stick blender until smooth.
Preheat the oven to 350 degrees. Combine the softened butter with the parmesan, oregano, garlic powder, and a pinch of salt.
Assemble the mini sandwiches by placing the mozzarella cheese in between 2 slices of bread. Spread the garlic butter on both sides.
Place on a parchment lined baking sheet. Bake for 15-20 minutes, flipping halfway through.
Serve with the creamy tomato soup!