For the Crust

1. Add flour, sugar, salt and butter to a food processor. Pulse until the flour and butter form coarse crumbs and then slowly add cold water and process until a dough forms. Pour the dough out onto a lightly floured surface and knead a few times until smooth and shape into a disk. If the dough is sticky, add a bit more flour. If the dough is crumbly, add a bit more cold water, and work it together. Wrap with plastic wrap and refrigerate for 8 hours or overnight.

For the Filling

1. In a medium pan, combine strawberries, rhubarb, sugar, orange juice and tapioca. Stir together over medium high heat. Bring to a gentle boil, stirring occasionally so it doesn’t burn on the bottom of the pan. When the strawberries and rhubarb have softened and the liquid thickens, about 5 minutes, remove the pan from the heat. Cool to room temperature and then cover and chill.

To Assemble

1. Allow the dough to sit out at room temperature for a bit before rolling out on a floured surface.
2. Preheat oven to 400 degrees.
3. Be patient as you roll, adding flour as needed and turning the dough to be sure it isn’t sticking to your work surface. Pat edges together if they crack.
4. Cut out twelve 3 by 3 inch squares, re-rolling the dough as needed. Place six squares on a parchment lined baking sheet. It is helpful to use a small metal spatula to transfer the squares. Spoon about 1 tablespoon of the filling in the center of each square.
5. Using a small pastry brush or your finger, wet the border of each square with water, and top with another square, pressing edges the two squares together carefully to seal the filling in. Use the blunt end of a wooden skewer (or the tines of a fork) to crimp the edges.
6. Brush the top of each fruit pocket with the egg wash and then sprinkle generously with cinnamon sugar. Poke a few holes in the top to allow steam to vent while baking.
7. Bake for 10-12 minutes, or until golden brown.
8. Transfer the fruit pockets to a cooling rack.