Basque cake

The cake is two components: a sweet shortcrust and a pastry cream filling, layered dough, cream, dough.

Separate eight eggs. Keep the whites in a covered container in the fridge -- whites age up to two weeks or more and old whites make the best meringue.

Sift the flour into a large bowl, then sift in the baking powder, then the sugar, mixing well with a spatula between each.

Cut fridge-cold butter into small cubes and press it into the flour with clean hands, working to a sandy mixture.

Do not knead or press it into a ball; flatten each lump of butter against the dry mix and keep going until all of it is sandy.

Grate lemon zest into the sandy mixture (optional).

Add the egg yolks and cut them through with a stiff rubber spatula, chopping down and rolling the dry mix over, not whisking, until it becomes a dough.

Knead it very briefly by hand, with the tiniest amount of flour, pressing down on either side in a star shape, and gather it into a ball. Do not knead much.

Weigh the dough and cut it into two equal halves rather than judging by eye -- 536 grams here, about 260-plus grams a disc.

Pre-shape each half flat in plastic wrap so it is easier to roll out, and rest it in the fridge at least an hour to cool.

For the pastry cream, put the milk in a pan with the scraped vanilla seeds and the half pod, and bring it gently to the boil over medium-high heat.

Beat the egg yolk with the sugar for a minute or so until the sugar dissolves a little, then mix in the corn starch and flour until the mixture falls in a ribbon.

Pour the hot milk through a sieve onto the yolk mixture and incorporate gently.

Pass the whole lot back through the sieve into the same pan, catching the foam.

Cook on medium, whisking constantly, until it thickens to a paste and bubbles form, then boil on very low heat one or two minutes.

Turn the heat off and stir a little piece of butter in until it melts.

Spread the pastry cream thinly on a tray with a heat proof spatula to cool it fast, lay food film touching the surface so no crust forms, and chill until cold.

Roll each cold disc of dough between two sheets of plastic wrap to a diameter of 20 centimetres, eight inches; the plastic keeps it flat and carriable and stops the cracking sheet breaking up.

If it cracks because it is too cold, turn it over, adjust the edges with a finger and keep rolling.

Return the rolled discs to the fridge on something flat.

Mix barely a teaspoon of rum into the cold pastry cream so it becomes malleable, and put it into a piping bag with a straight tip.

Work straight onto a baking tray lined with parchment paper. Mix one egg with a tablespoon of milk for the egg wash.

Take the first disc out of the fridge, leaving the second in. Handle it once and once only, remove the plastic and position it gently.

Brush egg wash around the outside three quarters of an inch of the disc, marking the boundary the cream must stop at and sealing the top layer on.

Pipe the pastry cream inside that boundary and spread it out to the line with a small spatula.

Lay the second disc of dough on top and press it down over the cream.

Push the tart ring down over the cake to cut it, and pull away all the excess dough outside the circle, using a knife to be neater.

Brush the top with egg wash, gently, so the dough does not crack.

Mark the top with the back of a fork wetted with a little water -- usually crosses.

Chill the cake in the fridge while the oven preheats to 180C, fan forced.

Bake 45 minutes at 180C with the fan on.

Wait 10 or 15 minutes before unmolding -- it is fragile hot -- then slide a knife all the way down around the inside of the ring and lift it off.

Cool on a rack and serve at room temperature at the warmest, ideally a little colder; rushing the cooling in the fridge wrinkles the top.

Variation: add jam.