Chop the onion into small pieces.
Mince the garlic cloves finely.
Open your canned tomatoes and set aside.
Melt butter in your large pot.
Add chopped onions and cook until soft.
This takes about 5 minutes.
Add minced garlic and cook 1 minute more.
Pour in the canned tomatoes with juice.
Add tomato paste and stir well.
Pour in the broth slowly.
Add sugar to balance the acidity.
Bring everything to a gentle boil.
Reduce heat and simmer for 20 minutes.
Stir occasionally to prevent sticking.
Use your immersion blender carefully.
Blend until completely smooth and creamy.
Be careful of hot splashes.
Stir in the heavy cream slowly.
Season with salt and pepper.
Taste and adjust as needed.
Ladle into bowls while hot.
Garnish with fresh basil leaves.
Serve with crusty bread or grilled cheese.