Allow the store bought pie crust to come to room temperature.
Unroll the pie crust onto a flat, floured surface. Sprinkle the crust with a little more flour, and then roll with a rolling pin until the dough is about 1/8" thick. You want the crust to be thin but not too thin that the crust rips.
Using a rectangular shape (I used a glass dish that was 4" wide x 5.5" long), with a sharp knife or pizza cutter, cut out 4 rectangles and set aside. With the leftover dough use a heart cookie cutter to cut out heart shapes. Take the remaining crust scraps, roll into a ball, and then roll out into a 1/8" thicknesses and cut additional heart shapes (the dough may not be big enough for additional rectangles).
Select which rectangle & heart shapes will be the "bottom" of the pop tart. On the bottom pieces, spoon about 1-2 tablespoons of the jam in the center of the shape. With the back of a spoon spread jam slightly leaving about a 1/4"-1/2" edge to seal the pop tart.
For the "top" crust of the pop tart, take small heart cookie cutters and cut out heart shapes from the dough (or you can omit this step for a more traditional looking pop tart). Or, layer on heart cut outs to the top of the pop tart.
With a finger, rim the bottom pie crust with milk. Lay the top layer of each pop tart onto the bottom and press the edges together with fingers.
Take the back of a fork and crimp the top & bottom edges of the pop tart together making sure to fully seal. Carefully move the pop tarts to a parchment lined baking sheet.
Brush the top of each pop tart with milk.
Bake in the oven at 375 degrees for 15-20 minutes or until the pie crust is golden brown.
Allow to cool and enjoy!