Gâteau Basque

Ingredients

• For the pâte
• 250 g unsalted butter, softened, not melted
• 200 g caster sugar
• 3 whole eggs, at room temperature
• 1 egg yolk, at room temperature
• 300 g plain flour
• 100 g ground almonds
• 1 tsp baking powder
• 1 vanilla bean, seeds scraped
• For the crème pâtissière filling (or substitute confiture)
• 300 ml crème pâtissière, thick, flavored with rum and vanilla, cooled completely
• 1 tbsp dark rum, stirred into the crème
• For the cherry filling (alternative)
• 300 ml confiture de cerises noires d'Itxassou, or Amarena cherry preserves as closest substitute
• To finish
• 1 egg, beaten, for egg wash
• butter, for the mold

Method

1. 1
   Cream the softened butter and sugar together until the mixture is pale and fluffy. The mass should hold its shape and show no visible grains of sugar.
2. 2
   Add the three whole eggs one at a time, incorporating each fully before adding the next. Add the yolk last. The batter should remain smooth and emulsified after each addition.
3. 3
   Fold in the flour, ground almonds, baking powder, and vanilla seeds. Work only until the dry ingredients disappear into the dough — this is where the dish lives or dies: overworking develops gluten and the pastry will bake tough rather than tender and sandy. The finished dough is soft, slightly sticky, and rich.
4. 4
   Wrap the dough and refrigerate for 1 hour. It will firm to a consistency that can be pressed and rolled without tearing.
5. 5
   Butter a 24 cm round mold. Press two-thirds of the dough evenly across the base and up the sides to form a shell. Spread the filling — crème pâtissière (stirred with rum) or cherry preserves — in an even layer, leaving a clear border at the rim.
6. 6
   Roll the remaining third of the dough to a round of approximately 24 cm and lay it over the filling as a lid. Press the edges firmly to seal. Brush the surface with beaten egg wash, then score the traditional crosshatch lauburu pattern with a fork.
7. 7
   Bake at 170 °C for 40–45 minutes. The gâteau is done when the top is deeply golden and the dome is set — a pale or yielding top indicates underbaking.
8. 8
   Remove from the oven and allow to cool completely in the mold before unmolding or cutting. The filling sets, the pastry firms, and the flavors meld during this rest. The cake is ready when it is firm to the touch at the center and cuts cleanly.