Heat olive oil in a large pot over medium heat.
Add diced onion and cook until translucent, about 5 minutes.
Add minced garlic and cook for another 1 minute until fragrant.
Add chopped yellow tomatoes, sugar, salt, black pepper, and smoked paprika to the pot. Stir to combine.
Pour in vegetable broth and bring the mixture to a boil.
Reduce heat to low and simmer uncovered for 20 minutes, stirring occasionally.
Remove the pot from heat and use an immersion blender to puree the soup until smooth. Alternatively, carefully transfer the soup in batches to a blender and puree until smooth.
Return the pureed soup to the pot and stir in the heavy cream and fresh lemon juice.
Heat the soup gently over low heat until warmed through, about 5 minutes. Do not boil after adding cream.
Adjust seasoning with additional salt and pepper if needed.
Ladle the soup into bowls and garnish with chopped fresh basil leaves before serving.