Makes two 8 1/2" tarts or one 11" tart
There will be a temptation with this dough to add water – don’t. Just keep working it. It will come together into a dough the texture of sugar cookie dough. You can make this pastry in a mix master, food processor, or by hand by working the butter in with your fingers. The ideal pan is a fluted tart pan with a removable bottom, although you can also make it in a shallow pie plate too.
¾ cup + 2 tbsp soft butter
1 cup sugar
3 cups all-purpose flour
1 tsp baking powder
½ tsp vanilla or zest of ½ a lemon
¾ - 1 cup jam, ideally one that is tart like apricot jam
Preheat oven to 350°F.
In a stand mixer fitted with the paddle attachment, combine the butter, sugar, flour, eggs, baking powder, and vanilla or zest. Mix the ingredients together on medium-low speed until the dough comes together like sugar cookie dough. Be patient, this will take a few minutes. If making by hand, just keep working the dough. It will come together.
Form the dough in a ball. Cut off ¼ of the dough and set aside. Flatten the large piece and work it into the bottom of the tart pan and up the sides. Finish off the edges so they are nice and neat and tidy.
Spread the jam on the bottom of the tart shell. With the remaining dough, roll bits into snakes and create a lattice top for the tart.
Bake for 35-45 minutes. Cool completely before removing from the pan. Serve at room temperature.