Roll out the pie crust to about 1/4 inch.
Use the heart-shaped cookie cutter to cut out two hearts.
Place the jelly onto one of the hearts ( used about 1 teaspoon for a 3-inch size heart), and spread it around making sure to leave a border on the edge of the heart shape.
Place the other heart shape over top and seal the edges by crimping them with a fork.
Use the fork to poke some holes on the top heart.
Repeat with the rest of the pie dough and place them in the fridge (I place mine on a lined baking sheet) while the oven preheats to 400 degrees.
When the oven is ready, remove the hearts from the fridge and place them on a baking sheet lined with parchment paper.
In a small bowl, whisk the egg and water together.
Use a pastry brush to lightly brush the egg wash onto the heart.
Bake for 12-15 minutes, or until lightly puffed up and golden. Timing will vary based on the size of the pop tart.
Allow the pastries to cool completely.
When the pastries have cooled, get the icing ready by whisking together the powdered sugar and half and half by starting with just 1 tablespoon. Add the second tablespoon if the icing is too thick. If the icing becomes too thin, add some more powdered sugar. Make it as thin or as thick as you like.
Sprinkle with Fancy sprinkles!
Allow the icing to set, and then serve.