Step 1

Place flour, icing sugar, cocoa, hazelnut meal and butter in a food processor. Process until combined. Add egg yolk and water. Process until dough just comes together. Shape dough into a disc. Wrap in plastic wrap. Refrigerate for 30 minutes.

Step 2

Preheat oven to 200C/180C fan-forced. Grease a 3cm-deep, 24cm round loosebased fluted flan tin.

Step 3

Roll out pastry between 2 sheets of baking paper until large enough to line base and side of prepared tin. Push pastry into tin. Trim edges. Place on a baking tray. Line pastry with baking paper and fill with pie weights or uncooked rice.

Step 4

Bake for 10 minutes. Remove baking paper and weights or rice. Bake for a further 5 minutes. Cool for 15 minutes. Spoon hazelnut spread over base of pastry case, spreading to level. Cool completely.

Step 5

Reduce oven to 180C/160C fan-forced.

Step 6

Make Filling: Using an electric mixer, beat eggs and sugar until thick and creamy. Add vanilla. Beat to combine. Add sifted flour and cocoa. Beat until just combined. Gradually beat in butter until combined. Pour mixture into pastry case (see note).

Step 7

Bake for 40 minutes or until filling is just firm to touch. Cool in pan. Drizzle tart with extra hazelnut spread and serve with ice-cream.