Place the flour and sugar into a food processor. Pulse a few times to combine.

Add the cold cubed butter and pulse until combined, the butter should be broken up and there should be no butter pieces larger than a pea.

Add the vanilla. Slowly stream in the water while the food processor is running. You want the crust to just come together, do not overmix.

Form the crust into a ball and cover with plastic wrap. Place in the refrigerator for 20-30 minutes to chill.

Preheat the oven to 400°F. Line a large sheet tray with parchment paper, and set it aside.

Make the filling by stirring together the brown sugar, butter, flour, and cinnamon until fully combined and set aside.

On a lightly floured clean work surface, roll out the dough into a 1/4th inch thick rough rectangle shape.

Using a 3x4 inch rectangle cookie cutter or something of similar size, cut out rectangles from the dough. You will need to roll out the scraps of dough again to cut more rectangles. We need 12 pieces.

Place 6 of the crusts onto the prepared sheet tray, not touching.

Place just under 2 tablespoons of the filling into the center of each crust with a ¼ inch border.

Top with another crust and gently press down the edges. Take a fork and press the edges together to seal. Take the same fork and make 6 rows of ventilation holes over the center of the tarts.

Bake for 15-18 minutes until golden brown. Let cool completely.

For the glaze, whisk together the powdered sugar, cinnamon, milk, and vanilla extract. We want the glaze very thick but still pourable. Start with 1 tablespoon of the milk and add a little more at a time until the desired consistency.

Place the tarts onto a wire rack over a sheet tray to catch any drips. Spoon the glaze on top of the tarts. Let the glaze set for 20 minutes.