Place turkey, ham and cheese on 10 bread slices; top with remaining bread. Cut each sandwich diagonally in half., Prepare pancake mix according to package directions. Dip sandwiches in pancake batter, allowing excess to drip off. Freeze sandwiches on waxed paper-lined baking sheets until firm. Transfer to freezer containers; return to freezer., To use, in an electric skillet or deep-fat fryer, heat oil to 375°. Fry frozen sandwiches, a few at a time, until golden brown, 3-4 minutes on each side. Drain on paper towels; sprinkle with confectioners' sugar. Combine sour cream and preserves; serve with sandwiches.