Heat oven to 450°F. Remove pie crusts from pouches; unroll on work surface. Cut eight 3 1/2-inch rounds from each crust.
Place 1 unbaked cookie in center of each of 8 of the rounds; top each with 1 fruit snack. Brush edge of each crust with water. Top with remaining 8 rounds. Press edges together with fork to seal. Brush top of each with water; sprinkle with sugar.
Bake 10 to 12 minutes or until golden brown. Cool. Mix powdered sugar and milk until smooth, adding milk until thin enough to drizzle. Drizzle glaze over pies; let stand until set, about 30 minutes.