Mocha meringue torte with hazelnut crumble

This one came to be because it was a friend's birthday. Not just any friend, but another food blogger. Not just any food blogger, but a food blogger who has been to Paris to study Cordon Bleu cookery (Francine's blog is here). I stupidly suggested I'd make a cake, and then realised I wouldn't be able to whip up one of my standards. Oh no. This would require ingenuity. Something that looked and tasted seriously adult, yet essentially remained cake-like. Something I couldn't muck up, yet something that looked like it required effort. Voila. The base is adapted from a chocolate meringue cake with coffee cream found almost anywhere, but the crumble is something I thought it needed just to take it over the edge.

Ingredients:

• 6 egg whites
• 1 1/2 cups caster sugar
• 1 tsp white vinegar
• 3 tbsp good quality cocoa (not just drinking chocolate powder)
• 1 1/2 tbsp corn flour
• 1/3 cup peeled hazelnuts
• 2 tbsp brown sugar
• 2 tbsp butter
• 1 tsp coarse salt
• 4 digestive biscuits (e.g Wheatens - substitute with oat bran/amaretti or other GF biscuit for gluten free)
• 200ml whipping cream
• 100ml custard (see note)
• 1 super sweet ristretto, cooled (really strong shot of coffee with lots of sugar and very little liquid)

Instructions:

1. Preheat oven to 150∘C, then beat egg whites to soft peaks. Gradually add caster sugar while still beating, then fold in vinegar, and sifted cornflour and cocoa. Spread into two large squares on baking trays lined with paper, about 2cm thick. Go gently, and try and spread evenly, but don't squish the air out - a wavy surface is fine. Bake for 1 hour, then slice through each square to form four rectangles, then replace in the oven, turn it off and leave the door ajar until trays are cool enough to touch. (about 20 mins)
2. While this cooking is going on, you might want to make your own custard, or nip down to the shop for some. Then start on the crumble. Grind the hazelnuts (a coffee grinder works well, or you can buy them already ground), then crumb in the biscuits, then rub together with the brown sugar and butter. toast in a dry pan for a few minutes, turning frequently. Switch off the heat as soon as the mix begins to colour, and continue to stir over until the pan cools. This is very easy to burn, so don't take your eye off it until the heat is out.
3. When the crumble and meringue is cool, start whipping up the cream until its firm enough to easily hold its shape on a spoon. Fold in the custard and coffee. The density will soften a little. 
4. Spread a quarter of the cream over one layer of meringue, then add another, and continue to layer like a lasagne. Finally cover with the crumble, then cover loosely with foil and place in the freezer for at least 2 hours before serving.

Note: Home made custard tastes heaps better if you can be bothered making it, and it will help use up those extra egg yolks. A tried and tested recipe here on www.taste.com.au

An easy recipe for any leftover crumble:
Use some puff pastry to cover the base of a ramekin. Add thinly sliced apple and custard, then cprinkle with cinnamon and sugar and cover with foil. Cook for 20 minutes at 180C, then add a little more custard and cover with crumble and cook for a further 10 minutes uncovered.