Send off summer and toast the arrival of fall with a spread that showcases the best of both seasons: Tart apples top these party-ready crostini, which pair beautifully with Plum Coolers.
Preheat oven to 425 degrees. On a rimmed baking sheet, arrange bread in a single layer and brush with 3 tablespoons oil. Season with salt and pepper and bake until golden, 10 to 12 minutes.
Top crostini with apple and prosciutto. Toss arugula with lemon juice and remaining tablespoon oil, season with salt and pepper, and divide among crostini.