Gâteau Basque Cake...adapted from a variety of recipes including ones from Dorie Greenspan, Gale Gand and Flickr
2 cups flour
3/4 teaspoon baking powder
1/4 teaspoon salt
10 tablespoons butter (5 ounces) at room temperature
1/4 cup brown sugar
1/4 cup sugar
1 teaspoon vanilla
For pastry cream:
2 cups whole milk
1 vanilla bean, cut in half lengthwise with seeds scraped and saved.
6 egg yolks
1/2 cup sugar
1/3 cup cornstarch
3 tablespoons butter, cut into pieces
1 tablespoon dark rum
1 teaspoon water
For garnish:Sauté 2 diced apples in a tablespoon of butter. Add sugar and brown sugar to taste (I used 3-4 tablespoons). When soft, add a tablespoon of dark rum or Calvados and cook till liquid evaporates.
Cream butter and sugar with paddle attachment of stand mixer. Add egg and vanilla, and mix for a minute or so. Sprinkle baking soda and salt over mixture and mix for a few seconds. Add flour in a few batches and mix till just combined.
Split dough in half. Roll out one half into an 8 inch circle between two sheets of plastic wrap. Repeat with other half of dough making this one just slightly larger. Place each onto a cookie sheet and allow to rest in refrigerator for a couple hours.
Make pastry cream by bringing milk, vanilla bean, and seeds to a boil in a medium saucepan. While the milk is heating up, mix together egg yolks, sugar and cornstarch in a large glass mixing cup or bowl. When milk reaches a boil, slowly drizzle about a half cup of the milk into the yolks while whisking so that yolks don't cook. When well combined, slowly pour yolk mixture back into saucepan and bring back to a boil, whisking continuously. Cook and whisk at least a minute after it starts to boil. Remove from heat and add rum and butter. Stir till well combined. Put pastry cream into bowl, cover with plastic and refrigerate till cold.
When the dough and pastry cream have cooled sufficiently, preheat oven to 350º. Butter an 8 inch cake pan. Place the smaller of the dough rounds into the bottom of the pan. Trim to fit. Place about 1 cup of the pastry cream in center of dough lined pan. Do not spread the pastry cream to the edge of the dough...leave about a one inch border without filling. Moisten the perimeter of the bottom layer with a bit of water. Place the larger second dough round over the pastry cream and press down along the edge to seal.
Whisk egg with water. Brush over top of cake. Use a fork to etch 3 evenly spaced paths across top of cake, then rotate cake about 45º and make 2 or 3 more evenly spaced paths. This should form a decorative cross hatch pattern. Bake 45 minutes. Cool about 5 minutes and remove from pan, then immediately flip back over onto serving dish so that finished side is on top. Allow to cool completely and serve with apples and a dusting of powdered sugar.