To make dough, combine flour and salt in a large bowl. Cut in butter until mixture resembles coarse crumbs. Stir in water, a tablespoon at a time, until mixture forms a ball. Separate into two balls, wrap in plastic, and refrigerate for 4 hours or overnight.

Place racks in the center of the oven and preheat to 400 degrees F. Line to baking sheets with parchment paper or silicone mats.

Remove pie crusts from the refrigerator and roll out to about ⅛ inch thickness. Using a heart shaped cookie cutter, cut approximately 10 hearts from the crust. Place these hearts on a tray in the refrigerator while you’re working on the second crust. After rolling and cutting out each crust, you should have approximately 20 hearts.

Beat your egg and water together to form the egg wash and lightly brush half of the hearts with the egg wash. Place a small amount of jam in the center of each heart. Gently place the remaining hearts over the top and use your fingers to seal the edges. Go over the edges with the tines of a fork for a final seal. Use a paring knife to cut three small vents on the top and brush each heart with the beaten egg.

Place the hearts on your prepared baking sheet and bake for 10-14 minutes. You want the tops to be golden and the filling to be bubbling. Remove from the oven and let cool for 10 minutes before serving.