In a bowl, mix the flour, sugar and salt. Grate the butter with a box grater into the flour. Toss to coat and lightly separate the chunks of butter.
Add one of the eggs and 2 tablespoons of milk. Stir to combine. If your mixture won't hold together, add milk 2 tablespoons at a time until the dough forms a ball.
Wrap in plastic wrap and chill the dough until just firm--about 30 minutes.
While the dough chills, make the filling. Place the freeze dried strawberries in a bowl. Bring the water to a boil either in the microwave or on the stove and pour over the berries. Stir to combine and then allow to soak for 30 minutes. Transfer the mix to a food processor or blend with a hand blender until smooth but thick. Do not strain out the seeds. Set aside.
Divide the dough in half and roll the dough to an 8x12 rectangle about 1/4" thick.
Cut down the center of the dough's length and make 3 cuts to make 8, 3x4" rectangles.
Beat the remaining egg with 1 tablespoon water. Brush over 4 of the rectangles.
Add about 1 tablespoon of the strawberries to the center of the egg washed rectangle.
Cover with the other piece of dough. Press the edges with a fork to seal and poke holes in the top with a fork.
Transfer to a parchment paper lined cookie sheet and chill in the refrigerator 30 minutes.
Preheat the oven to 400. Bake the tarts 25 to 30 minutes until golden and flaky. Remove from the oven and allow to cool before frosting.
To make the frosting mix the powdered sugar, vanilla and 1 tablespoon of milk. Frosting should be thick so just add a little milk at a time. Spread 1/2 tablespoon over each tart and sprinkle with natural sprinkles or raw sugar.
Once totally cool place tarts in an air tight container. Re-heat in a toaster oven or microwave.