buttery breton cake

Makes 25 squares

Preparation time 25 minutes, plus chilling and cooling

Cooking time 45 minutes

225 g (7½ oz) self-raising flour, plus extra for dusting

175 g (6 oz) icing sugar

2 tablespoons vanilla sugar (see page 168) plus extra for dusting

200 g (7 oz) chilled lightly salted butter, diced, plus extra for greasing

5 egg yolks, plus 1 beaten egg, to glaze

150 g (5 oz) strawberry jam

Sift the flour and icing sugar into a food processor, add the vanilla sugar and butter and blend until the mixture resembles coarse breadcrumbs. Add the egg yolks and blend to make a thick paste. Wrap in clingfilm and chill for at least 3 hours or overnight.

Grease and line an 18–19 cm (7–7½ inch) square shallow baking tin with nonstick baking paper. Press half the dough into the tin, spreading it into the corners with your fingers so the dough forms an even layer. Spread the jam over the dough, leaving 1 cm (½ inch) clear around the edges.

Roll out the remaining dough on a floured surface to the same dimensions as the tin and lift into place. Press down gently and brush with the beaten egg. Bake in a preheated oven, 190°C (375°F), Gas Mark 5, for 40–45 minutes until risen and deep golden. Leave to cool in the tin before transferring to a flat plate or board. Dust lightly with vanilla sugar and cut into 25 squares.

For homemade strawberry jam, tip 1 kg (2 lb) strawberries into a large saucepan or preserving pan and add the juice of 4 lemons. Cook gently for 10 minutes or until the strawberries are soft. Add 1 kg (2 lb) granulated or preserving sugar and heat until the sugar dissolves. Boil for about 15–20 minutes until setting point is reached. To test for setting point, put a teaspoonful of the jam on a chilled saucer and place in the fridge for 2 minutes. Push the cooled jam with your finger. If the surface wrinkles, then setting point is reached. If still syrupy, boil the jam for a little longer. Avoid boiling the jam for too long or it will lose its strawberry flavour. Put into sterilized jars, cover and label.