Although the dormouse says the tarts are filled with treacle, and the Cook tells the King the filling is pepper, I have always imagined that the stolen tarts in Alice in Wonderland were jam tarts.
Jam tarts are simple. All you need is your favourite pastry dough and jam. You can even use freezer pie crust. Since today’s tarts will be made from squares, you need to roll out your dough in a square.
If you are starting with a pre-made pie crust, it will be circular. Here is a simple way to turn that circle into a square.
Lay out your circle of dough on a work surface, and fold the top third down. (Please note, the images were done using a paper circle, not an actual pie crust.)
Fold the bottom third up.
Rotate 90°, and fold the top third down.
Fold the bottom third up and roll out, keeping your dough as square as possible.
The next step is best done with a ruler. (Yes, I keep a ruler in the kitchen.) Cut your pastry into squares. The paper model was done with a 10 cm/four in square, but I made the real tarts with 7.5 cm/3 in squares. The border strips are cut 1.25 cm/0.5 in wide in both cases.
Cut your squares to the size you want, then cut internal slits following the diagram below. Make sure to leave two opposing corners intact.
Moisten the border strips outside the slits.
Fold the top left corner down to match the bottom right corner of the inside square, and press firmly enough to adhere the two layers of dough but not hard enough to push them out of shape.
Fold the bottom right hand corner up to match the top left corner of the inside square. Press as before.
Place pastry shapes on a baking sheet and prick the centre square of each one all over with a fork to reduce puffing in this area. Bake at 220°C/Gas Mark 7/450°F until pastry is just beginning to brown, rotating the pan once about halfway through. (You can skip the rotating if you are using a convection oven.) This took about 12 minutes in my oven using whole wheat pastry dough. Times will vary with the dough you are using and your oven. Start peeking at about 10 minutes if you aren’t sure.
When the pastry is done, remove the pan from the oven and let the tart shells cool in place until they are stiff enough to move easily. Finish cooling the shells on a wire rack.
Fill the shells with your favourite jam just before serving.
You can make the tart shells ahead. After baking, they will store for a week in an airtight container, or in the freezer for much longer. If you are starting with home made pastry dough you can freeze the shells before baking, then bake as many as you want from frozen. Just allow a little longer cooking time.