Stir together tomatoes and chicken broth in a large saucepan; bring to a boil, reduce heat to medium-low, and cook at a simmer until slightly reduced, about 10 minutes.

Stir in basil and sugar; reduce heat to low and continue cooking until basil is wilted, about 5 minutes.

Stir cream into tomato mixture; add butter and continue cooking, stirring occasionally, until butter is completely melted, 5 to 7 minutes more.