1. Mix Dry Ingredients: In a food processor or large bowl, pulse/whisk together the gluten free flour, sugar, and salt.

2. Cut in Butter: Add the cold, cubed butter. Pulse or use a pastry blender until the mixture resembles coarse crumbs with some pea-sized pieces of butter remaining.

3. Add Wet Ingredients: In a small bowl, whisk together the cold egg and the ice water. Slowly drizzle this into the flour mixture while pulsing (or stirring) until the dough just starts to come together. Do not overmix.

4. Chill Dough: Turn the dough out onto plastic wrap, form it into a disc, wrap tightly, and refrigerate for at least 1 hour.

5. Prep & Preheat: Preheat oven to 375°F (190°C). Line a large baking sheet with parchment paper. In a small bowl, mix the strawberry jam with the cornstarch (this prevents the filling from leaking).

6. Roll Out: On a lightly floured surface, roll the chilled dough out into a large rectangle about 1/8 inch thick. Using a sharp knife or pizza cutter, cut the dough into rectangles (approx. 3×4 inches). You should get about 14-16 rectangles (making 7-8 pop tarts). Re-roll scraps if necessary.

7. Fill: Place half of the rectangles on the prepared baking sheet. Place a generous tablespoon of the jam mixture in the center of each, leaving a clear border around the edges.

8. Assemble: Brush the edges of the filled rectangles with a little water. Place a second rectangle of dough on top. Use a fork to crimp the edges tightly to seal.

9. Bake: Whisk the remaining egg with 1 tablespoon of water to make an egg wash. Brush the tops of the pop tarts. Use a toothpick or fork to poke a few holes in the top for steam to escape. Bake for 20–25 minutes, or until golden brown.

10. Cool & Glaze: Let the pop tarts cool completely on the pan. While cooling, whisk the powdered sugar, milk, and vanilla until smooth. Spoon the glaze over the cooled pop tarts and top with sprinkles. Let the glaze set before serving.