Unroll the pie crusts, place on a lightly floured work surface, and roll the crusts slightly with a rolling pin to square the edges. Cut each crust into 8 equal-sized rectangles. Place about 2 teaspoons of strawberry jam in the center of 8 squares, and spread the jam out to within 1/4 inch of the edge of the pastry square. Top each with another pastry square, and use a fork to crimp the squares together, sealing in the jam. Use a knife to trim the pastries, if desired. Move the filled pastries to the prepared baking sheets.