Nigella Challenge: Gateau Breton

This is a cross between pastry, shortbread and cake. It's ridiculously buttery and delicious. So simple its incredible. You can definitely whip this up at short notice.

• 225g plain flour (use Italian 00 if you can find it - a very fine pastry flour)
• 250g caster sugar
• 250g unsalted butter, cubed
• 6 large egg yolks

Preheat oven to 190C. Line a 23cm springform pan.

Sift flour if using ordinary plain flour (not if using 00). Stir in sugar then add butter and egg. Reserve 1 tsp egg yolk. Use hands to knead the dough. Alternatively, you could use the dough hook on an electric mixer. Knead/mix until smooth. 

Scoop dough into pan and smooth out. Mix the reserved egg with 1 tbsp water to make a glaze and brush over the gateau. 

Bake for 15 minutes, then turn down oven to 180C (170C fan-forced) and bake a further 25 minutes until it's golden and firm to touch. Cool completely in tin before removing so that it doesn't fall apart. 

This is a brilliant after-dinner treat topped with berries or makes a delicious mid-morning treat.