I got this recipe from the Yum Yum magazine.
Sponge cake ingredients:
175 gm. Optima sponge mix
4 nos. eggs
30 gm. ground hazelnut
1/2 tsp. Ovalette
50 gm. cornoil
For hazelnut mixture, mix them all together. If the mixture is not spreadable, add in some more eggs. Mix until you can spread with a palette knife.
200 gm. Ground hazelnut
40 gm. caster sugar
3 nos. eggs
1 tsp. Vanilla Essence
2 - 3 Tbsp. Rum (optional)
Some strawberry jam
Method for sponge:
(1) Beat all the ingredients together except cornoil until thick.
(2) Fold in corn oil and pour into an 8" round tray.
(3) Bake at 180C for about 45 mins.
(4) Remove from oven and leave onto wire rack to cool.
(5) Slice cake into 3 layers.
(6) Spread strawberry jam on each layer of the sponge cake and stack them together.
(7) Spread hazelnut paste onto the whole cake and then pipe lines on top alternating with the strawberry jam.
(8) Put the whole creamed cake into an oven and bake at 175C for about 15 to 20 mins. Cool before slicing.
P/s. I piped the strawberry jam and bake together with the hazelnut paste to give it a stiffer texture so that when you slice the cake, it's not so runny. I have made some slight changes to the recipe to suit my preference.