Prepare the Crust

1. In a large bowl, combine the flour, salt, and sugar (if using). Add cubed butter and use a pastry cutter or your hands to blend the butter into the flour until it forms a crumbly texture. Gradually add cold water, one tablespoon at a time, until the dough comes together into a ball. Avoid overworking the dough. Wrap the dough in plastic wrap and chill in the refrigerator for about 2 hours, or up to 5 days.

Make the Peach Compote

1. In a small saucepan, combine the chopped peaches, brown sugar, vanilla extract, cinnamon, cornstarch, and salt. Cook the mixture over medium heat, stirring occasionally, until the peaches break down and the mixture thickens. Do not let it boil. Remove from heat and transfer to a bowl. Let the compote cool completely before using.

Roll Out the Dough

1. Preheat the oven to 425°F (220°C). Lightly flour a clean surface and roll out half of the dough until it is paper-thin. Trim the edges and cut the dough into six rectangles. Repeat with the second half of the dough to create a total of 12 rectangles.

Assemble the Pop-Tarts

1. Spoon about 1 heaping teaspoon of peach compote onto half of the dough rectangles, leaving a small border around the edges. Place the remaining dough rectangles on top of the filled ones. Use a fork to crimp the edges of each pop-tart to seal. Make 3-5 small slits on the top of each pop-tart to allow steam to escape.

Bake

1. Place the assembled pop-tarts on a greased or parchment-lined baking sheet. Bake for 7-9 minutes, or until the edges are golden brown. Allow them to cool slightly on a wire rack.

Glaze and Decorate

1. In a small bowl, whisk together powdered sugar and almond milk (or whole milk) until smooth. Drizzle the glaze over the cooled pop-tarts and sprinkle with colorful sprinkles if desired. Allow the glaze to harden before serving.