Gateau Basque

A year and a half ago we spent three weeks in the Basque region of France. Early in our stay we went to the weekly market in St. Jean Pied de Port and bought a traditional pastry, a gateau Basque, from a vendor there. We loved it and when we finished it we bought several others at other locations. Unfortunately none of the others were nearly as good in our opinion and when we returned to the weekly market we never saw that first vendor again. I have wanted to try making a gateau Basque but have been worried about it because we found that they varied so much. There are two basic types. One is filled with cherry preserves and the other is filled with pastry cream. We prefer the type with pastry cream but there are lots of variations in the recipes and I had no idea what made the difference between a tasty cream filled gateau Basque and a meh one.  I combined several recipes and happily came up with a result we liked.
A couple of the recipes warned that the dough used to enclose the cream filling is very soft and sticky. The warning did not prepare me for how very soft and sticky the dough is. When I had the gateau assembled in the pan, it was not a pretty sight and I was very worried. Fortunately as it baked, the pastry smoothed and it ended up looking very nice. The dough recipe makes more than is needed, but not a lot more. One recipe suggested using the extra dough to make cookies, but they would be very difficult to shape with such a soft and sticky dough and so I don't know that it is worth it for a few cookies. The dough should be rolled between sheets of plastic wrap. Flour the bottom piece of wrap and flour the top of the dough before placing the wrap on top of it. Flip the plastic wrap covered dough several times as you roll it out to keep the surface as smooth as possible.
If you decide to grind your own almonds, you can easily do it in a food processor. Pulse blanched sliced almonds with at least 2 tablespoons of the sugar. The sugar will keep the almonds from heating up and getting oily or worse, turning into almond butter.
I served the gateau Basque with unsweetened sliced strawberries on the side and the combination was delicious. One recipe I saw included brandied cherries dropped onto the cream filling and that would be nice.

Gateau Basque
Dough
1 1/2 cup granulated sugar
2 1/4 cup all purpose flour, sifted
90 grams (3/4 cup) finely ground almonds (same as almond flour)
1 1/2 tsp baking powder
1/2 tsp salt
2 sticks (1 cup) unsalted butter cut into chunks
3 large eggs, lightly beaten
1 1/2 tsp vanilla extract
zest of 1 lemon, preferably Meyer
Whisk the dry ingredients together. Place in bowl of electric mixer and put butter chunks on top. Beat  with paddle attachment until butter is incorporated and the mixture looks sandy. Combine eggs, vanilla, and lemon zest and beat into butter mixture just until combined. Divide dough into 2 disks on plastic wrap, one slightly larger than the other. Wrap. Refrigerate at least 3 hours.
Pastry Cream
2 cups whole milk
6 large egg yolks
1/2 cup sugar
1/3 cup cornstarch sifted
1 vanilla bean
1 to 2 tblsps Kirsch
3 1/2 tblsp butter cut into bits, at room temperature
Place the milk into a small saucepan, add seeds from the vanilla bean, and bring to a simmer over moderate heat, stirring often. Whisk the cornstarch and sugar together. Place the egg yolks into a medium heavy bottomed saucepan and whisk in the sugar mixture until thick and well blended. Whisk 1/4 cup of the hot milk into the egg yolks. Be sure to whisk without stopping and drizzle the milk in slowly. Still whisking, add the rest of the milk in a steady stream. Place the pan over medium heat and whisk vigorously, constantly and throughly, making sure to get the edges of the pan. Bring the mixture to a boil and boil 1 to 2 minutes, until thickened. Remove from heat and add kirsch and butter and stir until smooth. Place the pan in ice water to cool and then place plastic wrap on the surface of the pastry cream and refrigerate until cold.
Assembly
Preheat the oven to 350º F and butter a 9" springform pan.
Roll out the larger disk of dough between pieces of plastic wrap as instructed in introduction into a 12" circle. Peel off the top layer of wrap, flip so that the exposed surface of the dough is down as you lower the it into the pan. Pat the dough into place in the pan and then peel off the other layer the of plastic. The dough will come up the sides of the pan. Spread the cooled pastry cream onto the surface of the dough. Roll out the other disk. It should be the same thickness but the diameter will be smaller. Place over the pastry cream in the same manner as the first circle was placed in the pan. Press the dough over the cream. The dough will come up the sides. Press the two layers of dough together and then trim it so that it is no more than 1/2" above the top of the top layer.
Egg Glaze
1 egg
1 tblsp milk
Beat egg and milk together and then brush over the top of the gateau. Use the tines of a fork to make a crosshatch pattern on the top.
Baking
Place the gateau Basque on a cookie sheet on the bottom rack of the oven and bake 20 minutes. Then rotate and place on a rack 1/3 of the way from the top of the oven and bake for about 35 or 40 minutes, until the top is golden brown. Cool 10 minutes, run a blunt knife around the edges, and remove the sides of the springform pan. Allow to completely cool before serving.
Makes 10-12 servings