• Gather the ingredients so you have everything close at hand on the counter or table. (Please note that the pastry dough needs to be refrigerated for at least an hour, although I let mine set overnight. This allows me to prepare the pop tarts the next morning to bake and serve fresh for breakfast or a morning snack.)

Prepare the Pastry Dough

• In a medium bowl, combine the all-purpose flour, granulated sugar, and kosher salt.
  2 cups all-purpose flour, 2 teaspoons granulated sugar, 1 teaspoon kosher salt
• Add to this small pieces of butter, and vegetable shortening. Cut in with a blending fork until crumbly.
  1/2 cup butter, 1/2 cup vegetable shortening
• Add the sourdough discard and stir in until a ball forms. Cover the dough in plastic wrap and refrigerate for at least one hour or for up to 24 hours.
  1 cup sourdough discard

Roll the Pastry Dough

• The next morning, or when the dough is chilled, preheat oven to 350°F. Roll out half of the dough using a rolling pin or pastry roller to make a 9″ x 12″ rectangle. (Try to form the rectangle as best you can at the corners.)
• With a pastry wheel or knife, make a horizontal cut through the center followed by 3-inch cuts diagonally so that you have eight 3″ x 4.5″ pieces, approximately. If desired, you may use a ruler to make exact cuts.
• Pierce holes in four of the tops with a roller docker or fork to allow the filling to escape while it bakes. Transfer the bottom pieces (4) to a baking sheet lined with parchment paper or a silicone baking mat, leaving at least 1/2″ between the tarts. (For easy transfer, dip your spatula in flour between each placement.)

Assemble the Sourdough Pop Tarts

• In a small bowl, whisk together 1 egg and 1 tablespoon of water to make an egg wash.
  1 large egg + 1 T water
• To begin assembling the pop tarts, brush each of the pastry pieces with egg wash. Then spoon about 2 tablespoons of jam onto the centers, spreading to within 1/2″ from the edges.
  1 cup peach jam
• Place the remaining four tops onto the bottoms, matching size and shape as best you can. Crimp the edges with tins of a fork to seal in the preserves.
• Next, brush the tops with the egg wash. At this point, you’ll have four pop tarts ready to bake. Repeat these steps with the remaining half of the dough.

Bake the Pop Tarts

• Bake the pop tarts in a preheated oven for 25-30 minutes until the edges are golden brown and the dough has cooked through.
• Remove the tarts from the oven and allow to cool for 10 minutes. Then transfer the pop tarts to a wire cooling rack. At this point, the pop tarts may be eaten, but I encourage you to ice them for the very best flavor!

Decorate the Pop Tarts

• Prepare the Vanilla Glaze by mixing together in a small bowl, the powdered sugar, hot water, and vanilla extract. Whisk until the sugar dissolves and drizzles in a light stream.
  1 cup powdered sugar, 5 teaspoons hot water, 1 teaspoon vanilla extract
• Spread the icing over the slightly warm tarts.
• Before the icing sets, sprinkle the pop tarts with decorating sprinkles.
  3 tablespoons decorating sprinkles
• Allow the Sourdough Pop Tarts to finish cooling until the icing has fully set before serving. Makes 8 Pop Tarts.