Blackberry cream cheese frosting gives summer sheet cakes a bright, tangy finish without sacrificing structure, as long as the puree is well reduced and the dairy base is mixed with care. With the right balance of sweetness, acidity, and chill time, it spreads cleanly, holds its shape, and serves well from a 9×13 cake.
Essential Concepts
Reduce puree; avoid watery frosting.
Use softened cream cheese and butter.
Add powdered sugar for structure.
Chill before serving; refrigerate after.
