In a food processor, pulse together flour, salt, sugar, and butter a few times, until the butter pieces are about the size of peas. Stream in the water, pulsing as you go.
Move the dough to a bowl or lightly floured surface and gently knead into a ball – be careful not to overwork the dough. Wrap in plastic wrap and shape it into a rectangle that's about 1/2" thick. Place the dough in the refrigerator to chill for 2 hours.
While the dough chills, blend your strawberries, honey, and lemon and strain through a fine mesh sieve directly into a saucepan to remove the seeds.
Cook over medium heat for 20-25 minutes, until the strawberry mixture is reduced to the point where you can scrape the bottom of the pan and the jam takes a little while to run back together again. Move to a bowl to cool.
Preheat oven to 300˚F and line a sheet pan with parchment paper.
Divide your dough in half and roll into a roughly 14 x 14" square on a floured surface. You should just barely be able to see the lines of your silpat or work surface through your dough, which should be about 1/8" thick. Make sure your surface is well floured, and sprinkle some flour on the dough before rolling.
Cut the dough into roughly 3.5 x 4.75" rectangles. You'll need to two for each pop tart. Combine your scrap dough and roll out again to minimize waste.
Spoon about a tablespoon of filling into each pop tart, then spread into a thin layer, leaving about 1/3" around the border. Beat an egg yolk and brush around the border of the jam. Dock the tops of your pop tarts with a skewer or a fork, then place over the bottom, and press down and then crimp the sides.
Bake for 30-35 minutes. They should be very lightly browned when you take them out, and the bottoms browned slightly.
Whisk together powdered sugar and milk until a thick glaze forms. Let pop tarts cool, then spread ~1 tbsp glaze on each pop tart and top with sprinkles.