I think for a gâteau Basque I want to go to a lady who really knows: Dorie Greenspan. This recipe is an American adaptation of a recipe she got in Basque Country (where she claims she ate gâteau Basque three meals a day).
10 ounces (2 cups) all-purpose flour
3/4 teaspoons baking powder
1/2 teaspoon salt
5 ounces (1 stick plus 2 tablespoons) butter, at room temperature
2 ounces (1/4 cup) light brown sugar
1.75 ounces (1/4 cup) sugar
1 large egg, room temperature
1/2 teaspoon vanilla extract
about1 cup black cherry preserves or pastry cream
1 egg beaten with 2 teaspoons water (for the glaze)
In a medium bowl whisk together the flour, baking powder and salt. In a mixer fitted with the paddle beat the butter and sugars on medium for about 3 minutes, until fluffy. Add the egg and beat about 2 minutes more, scraping down the sides of the bowl as needed. Add the vanilla and mix for about another minute. Reduce the speed to low and add the dry ingredients in two or three additions, mixing only until they just disappear. The dough will be quite sticky.
Lay a sheet of wax paper or plastic on the counter and put half the dough in the center of the sheet. Cover it with another piece of plastic or wax paper, then roll the dough into a circle a little more than than 8 inches in diameter. Repeat with the other half of the dough, then refrigerate both pieces for at least three hours.
When ready to assemble, preheat your oven to 350 and grease an 8-inch round cake or springform pan. Take the dough out of the refrigerator and let it warm up a few minutes. Peel off the wax paper and lay one layer in the pan. Press it into the corners. Spread the jam or pastry cream on dough, leaving a 1-inch border around the edge. Moisten the uncovered edge and lay on the second piece of dough, passing the edges to seal.
Paint on some egg wash and make the crisscrossing pattern on top or the Basque cross if you like depending on the filling! Bake for 40-45 minutes until well browned. Cool the can in the pan on a wire rack for 5 minutes, then run a knife around the edge of the pan to loosen it. Invert the cake onto another wire rack, then back again (or, if you’re using a springform pan, just release the clasp and slide the cake onto a rack. Cool completely and serve the same day.