Gâteau Basque, Black Cherries, Lemon Zest, Pastry Cream, and Black Cherry Jam
For the Cherry Sorbet:
Combine the water, glucose, inverted sugar, and sugar in a pot and bring the mixture to a boil. Add the black cherry purée and chill in an ice bath. Emulsify with a hand blender and divide into thirds to freeze in 3 separate Pacojet containers. Spin fresh every day.
For the Pâte Sucrée:
Cream the butter, sugar, light brown sugar, salt, and almond flour together. Add the eggs 1 at a time, mixing to combine, and add the vanilla extract. Sift the baking powder and all-purpose flour together. Add the flour mixture slowly to the creamed butter mixture, mixing to combine. Chill the dough for at least 4 hours.
For the Pastry Cream:
Combine the milk and cream in a pot and bring to a boil with the lemon zest. In a medium bowl, whisk the egg yolks, sugar, and pastry cream powder together. Temper the hot milk mixture into the egg mixture. Return the mixture to the heat and whisk until boiling; cook 1 minute more until shiny and thick. Remove from the heat, whisk in the butter, strain the pastry cream, and flash in the freezer for 15 minutes. Reserve in the cooler.
For the Cherry Jam:
Toss the cherries in the sugar. Combine the sugared cherries and water in a pot over a medium heat and cook until the cherries burst and turn jammy. Cool completely.
For the Lemon Curd:
Cook the sugar, lemon juice, and eggs over a water bath until they turn thick at about 80°C, whisking constantly. Remove from the heat and mix in the butter with a stick blender. Cool over an ice bath. Reserve some of the finished lemon curd for plating.
For the Gâteau Basque:
Between 2 sheets of parchment paper, roll out the Pâte Sucrée to ¼ inch thickness. If the dough gets soft, put it back in the cooler or freezer for a few minutes. Press into a tart or cake pan and trim the edges. Fill the unbaked shell a quarter of the way with Cherry Jam. Top off the unbaked shell by filling the remainder almost to the top with Lemon Curd. Put another sheet of dough on top and seal the edges. Put in cooler for at least 1 hour. Preheat the oven to 375°F. To bake, prick the top of the pastry with a fork several times. Lightly brush with the beaten egg. Bake until dark golden brown, 20 minutes for a small tart, up to 1 hour for a larger tart.
To Assemble and Serve:
Draw a line of the reserved Lemon Curd across the center of a rectangular plate. Put the Gâteau Basque one-third of the way across the line. Put several dots of Lemon Curd of varying sizes along the line. Plate a small pile of crushed Pâte Sucrée two-thirds of the way along the line. Warm the cherries and plate 6 halves along the line with the dots of Lemon Curd. Put a quenelle of Cherry Sorbet horizontally on top of the crushed Pâte Sucrée.