Prepare the Strawberry Filling: In a medium-sized pot over medium heat, combine chopped strawberries, cane sugar, and a splash of lemon juice. Stir frequently for about 10 minutes until thickened and syrupy. Remove from heat and let cool.

Make the Dough: In a large mixing bowl, cream together ½ cup unsalted butter and ¼ cup cane sugar until light and fluffy. Add 1 egg yolk and 1 teaspoon vanilla extract, mixing until smooth. Gradually incorporate 2 cups all-purpose flour and 1 cup sourdough discard until no dry flour remains.

Roll Out and Cut Dough: Turn the dough onto a lightly floured surface, roll into a 14-inch square, and cut into twelve rectangles measuring 4x3 inches each.

Assemble Pop Tarts: Spoon about 1 tablespoon of cooled strawberry filling onto half of the rectangles, brush edges with water, and seal with remaining rectangles. Press edges and use a fork to crimp and create small holes.

Bake: Preheat oven to 350°F (175°C), arrange pop tarts on baking sheet, and bake for 20-25 minutes until golden brown.

Glaze: Once cooled, whisk together 1 cup powdered sugar and 2 tablespoons milk. Drizzle over pop tarts and sprinkle with natural decorating sugars if desired.