In a large bowl, combine flour, sugar, and salt.

Add the butter to the dry ingredients, and cut the butter into the flour mixture until it resembles a coarse meal using a pastry cutter.

Pour 1-2 tablespoons of water into the dough at a time, and stir gently with a fork until the dough forms a ball, adding more water as needed. Divide dough into two balls of equal size, then wrap tightly in plastic wrap and allow to rest in the refrigerator at least 30 minutes. This dough keeps very well in the refrigerator for several days.

Combine all ingredients in a small saucepan over medium heat. Let cook 10-15 minutes until the strawberries can be mashed with the back of a spoon and form a thick jam. Place the jam in a small bowl and let cool in the fridge while you roll the dough.

Line a baking sheet with parchment paper or a silicone baking mat.

On a well floured work surface, or on a silicone baking mat, roll out one of the balls of pie crust into a large rectangle about 1/4-inch thick and roughly 14 x 9 inches. You can use a rectangular cookie cutter or a pizza cutter or a sharp knife and a ruler, to divide the dough into roughly 10 squares, about 2.5 x 4 inches. Set the 10 rectangles on the prepared baking sheet and let chill in the refrigerator while you roll and cut out the other half of the dough into 10 rectangles.

Remove the first ten rectangles from the refrigerator, along with the cooled strawberry filling. Place 1 tbsp of strawberry filling in the center of each rectangle. Brush the edges of each rectangle with a little bit of water. Place a second dough rectangle on top and use the tines of a fork to crimp and seal the edges. Use a fork to poke a few holes in the top layer of dough to allow the filling to vent as it bakes.

Preheat oven to 400 F.

Return the prepared pop tarts to the refrigerator to cool for 20 minutes while you preheat the oven (this prevents shrinkage). You can also leave the prepared pop tarts in the refrigerator on the baking sheet, wrapped tightly in plastic over night, or even freeze them. Then they'll be ready to bake when you're ready to eat.

Just before putting the pop tarts in the oven, whisk together the egg wash. Brush egg wash over the top of each pop tart.

Bake 18-20 minutes until the top each pop tart is golden brown. If staring from frozen, it may take an extra 5-10 minutes.

Allow the pop tarts to cool on the baking sheet while you make the icing.

Whisk together the icing ingredients. It is the correct consistency when you lift the spoon from the icing and the ribbon that drizzles off the spoon holds its shape for several seconds before dissolving into the bowl. Add more powdered sugar or milk as needed to achieve the correct consistency.

Use an offset spatula to cover the top of the pop tart with icing, then sprinkle with sprinkles, if using. Let the frosting harden for about 10 minutes before enjoying.