Preheat Oven: Set oven to 375°F (190°C) and line a baking sheet with parchment paper.
Roll Out Dough: If using store-bought pie crust, let it come to room temperature and roll it out slightly to remove creases.
Cut Rectangles: Use a pizza cutter or sharp knife to cut dough into 3 x 4-inch rectangles.
Add Filling: Spoon 1 ½ tablespoons of strawberry jam into the center of half the rectangles, leaving space around the edges.
Seal the Pop Tarts: Place another dough rectangle on top of the filled ones. Press edges together and crimp with a fork.
Brush with Egg Wash: Whisk egg and milk together, then lightly brush over the tops for a golden, crisp finish.
Poke Holes & Bake: Use a fork to poke small holes in the top. Bake for 12-15 minutes until golden brown.
Cool & Ice: Mix powdered sugar, vanilla, and milk into a smooth icing. Spread on cooled pop tarts and add sprinkles.