Mary Berry and Paul Hollywood get the new series of The Great British Bake Off 2015 up and running with the first technically challenge: Mary Berry’s frosted walnut cake recipe.

This delicious treat consists of a light sponge sandwiched with buttercream and covered with sweet meringue. It is one of Mary’s favourites, and none of the bakers wants to disappoint the queen of baking tackling one of her recipes.

The ingredients are: 200g plain flour, 1 pinch of salt, 1 generous tsp baking powder, 100g butter, softened, 225g caster sugar, 1 tsp vanilla extract, 2 eggs, separated, 100g shelled walnuts, roughly chopped and 100ml milk.

For buttercream filling: 75g butter, softened, 125g icing sugar, sifted, 1/2 tsp vanilla extract and Rose petals, or 8 walnut halves, to decorate.

For the frosting: 2 eggs, whites only, 425g caster sugar, or granulated sugar and 100 ml water.