Gateau Basque

Method

Cream butter and caster sugar together at medium speed for 4-5 minutes until pale and fluffy. Add three whole eggs one at a time, beating well between additions and scraping bowl frequently. Whisk in vanilla extract. Sift together flour, baking powder and salt, then fold gently into the wet mixture until just combined. Divide dough in half; roll one portion between two sheets of baking parchment to 5mm thickness, then place on a lined 23cm round cake tin base. Spread cherry jam or pastry cream evenly over this base layer, leaving 1cm border. Roll second dough portion to 5mm and place over filling. Make fork marks across the top in traditional crosshatch pattern. Beat one egg yolk with 10ml water and brush generously over surface. Chill assembled cake for 30 minutes at 4C. Bake at 180C (160C fan) for 35-40 minutes until deep golden brown. Cool in tin for 10 minutes, then turn out onto wire rack to cool completely.