Make the strawberry preserves: Remove stems and finely chop strawberries. (Skip if you're using frozen.)
226 grams strawberries
Add strawberries, sugar and lemon juice to a medium pot. Cook over medium heat until the sugar has dissolved. Turn the heat to high and boil for 1 to 2 minutes, stirring occasionally. You may need to cook your preserves for a few minutes longer if you use frozen strawberries. 57 grams cane sugar, ½ teaspoon lemon juice
Turn the heat back down to medium and simmer for about 10 minutes or until the strawberries have completely broken down and the consistency is thick.
Transfer to a glass jar and let cool to room temperature. Store extra in the fridge for up to 2 weeks.
Preheat the oven to 350°F. Line a baking sheet with parchment paper.
Make the dough: Stir the butter, sugars, and vanilla extract with a stiff spatula until combined and there’s no butter chunks.
57 grams unsalted butter, 57 grams cane sugar, 35 grams powdered sugar, 1 teaspoon vanilla extract
In a small bowl, add the sourdough discard and egg yolk and stir together.
57 grams sourdough discard, 1 large egg yolk
Add the flour to the butter mixture and add the egg yolk mixture on top. Mix on low until combined into a crumbly dough. Add in water as needed just until the dough comes together.
255 grams all purpose flour, ¼ teaspoon salt, 2 tablespoons water
Bring the dough together with your hands until a cohesive dough forms.
On a floured surface or a piece of parchment paper, roll out the dough to a 14-inch square about ⅛-inch to ¼-inch thick, the thinner the better!
Trim the rough edges into a 12-inch rectangle. Cut out twelve 4 by 3-inch rectangles.
Place 6 of the rectangles onto the prepared baking sheet.
To make the filling: Add the strawberry preserves and cornstarch to a bowl and mix together.
88 grams strawberry preserves, 1 teaspoon cornstarch
Assemble the tarts: Spoon about 1 tablespoon of filling onto the middle of each rectangle. Dab water around the edges of each filled rectangle. Top each with another rectangle of dough.
2 to 3 tablespoon water
Using a fork, crimp the edges. Then poke holes all over the top of the dough or make two slits with a sharp knife.
Bake for 20 to 25 minutes or until the edges are lightly golden brown on the bottoms. Allow to cool completely on the baking sheet.
Make the glaze: In a small bowl, add the powdered sugar and milk and whisk together until a smooth glaze forms. The glaze should be quite thick.
106 grams powdered sugar sifted, 1 to 2 tablespoons milk
Frost each pop tart with glaze and top with the decorating sugars.
natural decorating sugars
Store in an airtight container for up to 3 days.