If you don't have a pastry cutter, use the rim of a drinking glass to cut rounds from the puff pastry.
Preheat oven to 400°.
Combine the first 6 ingredients in a medium bowl. Place 1 sheet of pastry dough on a work surface lightly dusted with flour. Gently roll to a 10 x 12 1/2–inch rectangle. Cut the dough with a 2 1/2-inch round cutter into 20 rounds. Place on a baking sheet coated with cooking spray. Prick the dough liberally with a fork. Top each round with about 3/4 teaspoon cheese and about 2 teaspoons tomato mixture. Repeat procedure with remaining dough, cheese, and tomato mixture. Bake at 400° for 25 minutes or until golden, rotating pans once during baking. Sprinkle tarts evenly with salt. Sprinkle with basil leaves, if desired.