Preheat the oven to 400 degrees Fahrenheit.
Place the flour, Crisco, sugar, and salt in a large bowl. Use the pastry dough blender to mix the dough until the vegetable shortening is evenly incorporated.
Add the ice water 1-2 tablespoons at a time and mix with your hands until a cohesive pie dough has formed. Form the dough into a ball and wrap it in plastic wrap. Chill the dough in the fridge for at least 20 minutes.
Once the dough has chilled, remove it from the fridge and place it on a lightly floured surface. Cut the dough in half and set one half aside.
Roll the first half of the dough into a rectangle shape. Use a pizza cutter or sharp knife to cut the larger rectangle into 6 smaller rectangles. Try to make the sizes of these rectangles as equal as possible.
Place the 6 dough rectangles on a piece of parchment paper on your baking sheet. Repeat this process for the other half of the dough and set those rectangles aside.
Once all of your dough rectangles are cut, use a spoon to portion about 2 tablespoons of jam onto each of the 6 dough rectangles on the baking sheet. Spread the jam filling out slightly, leaving about 1/4 - 1/2 inch space from the edge of the pastry.
Next, take a second rectangle of dough and lay it on top of the first one. Use the prongs of a fork to press the two pieces together around the entire perimeter of the pastry.
Use a toothpick to create 8-10 small holes in the tops of the pop tarts. I find that it works best if you poke the dough and swirl the toothpick around a few times to make the hole a little bit bigger.
Bake the pastries in the oven at 400 degrees Fahrenheit for 13-15 minutes or until the edges of the pop tarts are golden brown.