In a large bowl, whisk together the flour, sugar and salt.
Add the butter and use your fingers to rub it into the flour until the mixture resembles coarse crumbs.
Slowly pour in the cold water, mixing gently until the dough comes together. Let the dough chill for one hour.
In a saucepan over medium heat, combine the butter, strawberries, vanilla, brown sugar, lemon zest, lemon juice, and a pinch of salt. Let mixture simmer for 5-8 minutes.
Stir in corn starch and let cook for another 1-2 minutes, until thickened.
Divide the chilled dough into two portions. On a lightly floured surface, roll out the first half to about ⅛ inch thick.
Cut out circles from the dough. Spoon about 1 tbsp of cooled filling into the center of each circle cut out, leaving a small border around the edges.
Roll out the second half of the dough and cut into thin, short strips using a knife or pastry wheel.
Lay the strips over the filled bottoms in a checkerboard pattern (weaving over and under), then trim to fit. Crimp by hand or fork if preferred. (Optional: brush the pastries with egg wash and sprinkle brown sugar on top)
Bake at 350F for 30-35 minutes or until golden brown (keep your eye on it!).
Let cool, serve and enjoy!