Heat oven to 375° F. In a large bowl, combine the chicken, corn, raisins, cilantro, ½ teaspoon salt, and ¼ teaspoon pepper.
With a 4-inch biscuit cutter, cut 4 circles from each piecrust.
Spoon the chicken mixture onto half of each circle, leaving a border. Brush the edges with water, fold in half, and press with a fork to seal.
Transfer to a baking sheet and bake until golden, 20 to 25 minutes.