Heat oven to 350 (180C) and line a 11” x 7” baking pan with parchment paper.

Mix the flour, cornflour, baking powder, sugar and butter in a food processor for about three minutes. Add egg yolk and vanilla essence and process for another couple of minutes. The mixture should resemble fine breadcrumbs.

Press this mixture firmly into the baking pan (you may think due to the consistency of this mix that it isn’t going to work out, but trust me, it will!). Bake for 12 minutes.

In the meantime prepare the topping by melting the butter, sugar and golden syrup in a saucepan. Once melted together simmer for 1 minute.

When the shortcake has been in the oven for the 12 minutes, remove and pour half the topping mixture over it. Sprinkle with the chopped walnuts, then cover with the remaining topping mixture.

Put back in the oven for 10 minutes (Keep an eve on the walnuts. If they start to colour up too much drop the oven temperature). Allow the slice to cool completely in the pan before cutting up.