Have ready a 9-inch square or round tart pan with a removable bottom.
Divide the dough into two parts: ⅓ and ⅔. Keep the smaller part refrigerated, wrapped while you work with the larger part.
Roll the large piece of dough on a lightly floured surface until you have a rough square a few inches larger than the pan. The dough is crumbly and if it tears as you roll it out simply patch it together. Make sure you make ¼ turns and flip it if you can to make sure it's not sticking to the surface. Lightly flour surface and rolling pin as needed.
Transfer the dough to the pan without stretching it. If it tears, just pat it together with your fingers. It's crumbly, so most of the time you'll be able to transfer a large piece and then have to patch the rest. That's fine.
Line the whole pan, bottom, and sides with dough, making sure the angles and corners are covered. With the rolling pin, a cornet, or a knife, level the rim by removing the excess dough.
Prick the bottom with a fork and transfer the unbaked tart shell to the freezer for 30 minutes (or the fridge for 1 hour) before baking. You don't need to wrap it unless you want to freeze it at this point. Preheat the oven to 350ºF (180ºC) about fifteen minutes before baking.
Roll the remaining dough on a lightly floured surface. Cut out stars or your favorite cookie shape, or cut strips (I use a pizza cutter) to make a lattice.
Spread the cold raspberry filling on the bottom of the cold unbaked dough you just took out from the freezer. Top with the cutouts, leaving space in between them; don't cover the jam completely.
If making a lattice, starting in the middle, carefully lay the longer strips first over the filling, going from side to side to form a crisscross pattern. Repeat with the rest of the strips leaving some space between them. Pinch the dough strips with the crust at the edges to seal.
Bake the tart for about 30 minutes, until the top is browned and dry and the filling starts to bubble.
Let cool on a wire rack for fifteen minutes or so, and make sure no jam is stuck to the sides, as it will harden as the tart cools. Let cool completely before removing it altogether.
Dust lightly with powdered sugar if you want before serving.