Hazelnut and Almond Gateau

Because we're now just 2 of us most of the time, I've decided not to join in any more challenges. I felt I was baking just for the challenges, and then we had to eat it. I know challenges are meant to do just that, but unless it's something that will fit in with us, I'm not going to join in.
So there will only be 'fancy' cakes as my Mum would say, when we have the children or visitors. But looking through my cookery books and great files of recipes, there are many simpler cakes I've never baked which we'd enjoy, so that's a challenge!
This cake came about because I found a packet of ground hazelnuts in my baking cupboard, and they needed using up. I've made this recipe before just using ground almonds, and replacing these with half ground hazelnuts worked fine; it made a slightly nutty cake. The filling is not the usual one for this recipe; It's a bit extravagant, but delicious.
It's such an easy recipe to do, and takes very little time to make. The filling is the longest part, and this could be changed to a simple chocolate butter cream or even Nutella!

Grease 2x18cm sandwich tins and lines them. Preheat oven 190C/gas5.

Whisk 4 eggs with 100g caster sugar till white and creamy. Fold in 50g ground hazelnuts and 50g ground almonds. Then fold in 50g plain flour. That's it - just spoon it into the tins, scatter 50g flaked almonds over the top and bake for 15-20 mins till nice and springy. Cool on a wire rack.

Filling:   Melt 100g dark chocolate, take off the heat and add 15g chopped up butter. Leave it to slightly cool.
Whip 300ml double cream till just holding its shape, then fold it into the chocolate mixture.Stir gently till mixed.
Put the cake without almonds on a plate and spread over the filling; put the other cake on top and chill for about and hour to let the filling set. Eat!

A nice light sponge with a nutty texture. There's a lot of filling, so maybe half the amount would be sufficient.
Nice contrast between the cake and the filling and the crunchy almond topping.