Torta alla gianduia: Coffee toffee meringues

This recipe is from Nigella's new book 'Kitchen' that just came out this month. I made the meringues to use up the egg whites I had left over from making custard base for strawberry ice cream. I didn't have the hazelnuts (which are optional) and left out the Frangelico (which I do have but wanted to keep it non-alcoholic for myself and my 2.5 yr old son) - though I think both additions would be yummy). I don't think you need anywhere near 600ml of cream! I got 8 meringues out of the recipe, and I only had about 150ml of cream, which was enough to top 4 meringues, so 300ml would probably be enough, depending on how much cream you put on each one. My oven is fan-forced - I didn't reduce the temperature to compensate, and the meringues were done after 35 minutes. Nigella says just to put the 'merest dribble' of sauce on, which I would agree with, so even though it doesn't make much, you'll probably end up with leftovers.

Coffee toffee meringues

Makes 8-10

For the meringues:
200g caster sugar
50g light brown sugar
2 tsp of instant espresso powder (mine was a bit granular, so I crushed it to a powder first)
pinch cream of tartar
4 egg whites
100g toasted chopped hazelnuts, for topping (optional)

For the toffee sauce:
15g butter
75g golden syrup
25g soft light brown sugar
60ml double cream
2 tsp Frangelico hazelnut liqueur (optional)

For the filling:
600ml double cream

To make the meringues:
Preheat oven to 140C / gas mark 1 and combine caster sugar, brown sugar, coffee powder and cream of tartar in a bowl, and set aside.
Whisk the egg whites in a dry grease-free bowl until soft peaks start to form. Begin to sprinkle in the sugar mix 1 tbs at a time while still whisking, until you have a glossy thick meringue. This process is much easier with an electric beater, or better still, a freestanding mixer. You need to allow adequate time between each addition for the sugar to dissolve. Undissolved sugar in meringue is what causes 'bleeding' - where you end up with syrup running out of the meringue. You can test whether the sugar is dissolved by rubbing a little of the meringue between your fingers - there should be no graininess.
Line a baking sheet. Spoon out dollops of meringue (about 2 big dessert spoonfuls) to give roughly 8-10 6cm circles. Spike or fluff the tops to give texture. I used 2 spoons to transfer blobs of mixture to the tray (one to scoop up some meringue, one to ease it off the spoon onto the tray), then used my clean finger tip to shape them. Sprinkle the top of each meringue with 1/2 tsp of chopped hazelnuts, saving the rest for serving.
Put in the preheated oven for about 45 minutes, by which time the meringues should be dry on the outside, but still gooey in the middle, and a little fragile to touch. Take them out of the oven, but do not remove them from the baking sheet.

To make the toffee sauce:
Melt the butter, golden syrup and light brown sugar in a pan over low heat, swirling gently (but not stirring) occasionally, then bring to a boil and let it bubble for 2 minutes. Take the pan off the heat and whisk in the 60ml of cream and liqueur. Pour into a small heatproof jug and leave to cool.

To serve:
Whip the cream until firm but not stiff.
Crush a dent into the top of each meringue (the shells will splinter a bit), then split it a little and fill from above with a dollop of cream. Drizzle on some of the sauce and sprinkle with some of the reserved chopped hazelnuts.

Meringues can be made 1 day ahead and kept in an airtight container. Sauce can be made a day ahead and kept in the fridge covered with Glad Wrap. Remove from the fridge 1-2 hours before needed to allow it to come to room temperature.