Daring Bakers July Challenge: Filbert (Hazelnut) Gateau with Praline Buttercream

When Chris of Mele Cotte chose Hazelnut Praline Gateau for this months challenge I was thrilled. My favourite chocolates are pralines and so using that flavour for a cake sounded a wonderful idea and it so was. This cake is amazing. The toasted hazelnuts used in all components of the cake give a fabulous flavour and aroma.

I decided to half the recipe as I didn’t want too large a cake. The Hazelnut Genoise was light and tender and dotted with tiny nuggets of hazelnuts. The toasted hazelnuts worked so well in the cake that when I tasted a few scrapes of the cake from around the tin I had to prevent myself from not taking a bite out of the cake before it was finished.

I used a little rum in the syrup which gave it flavour but I was careful not to add too much. I then used amaretto in the buttercream to enhance the nutty flavour but didn’t add any more liqueurs to any of the other components as I wanted the hazelnuts to be the main flavour.

For the praline paste I used hazelnuts which were pre chopped which worked well as it meant they got more of an even coating in the caramel. I ate a bit of the brittle before I blitzed it and it tasted so good, the caramel coating really enhanced the praline flavour. I saved a few of the brittle pieces back to help decorate the top of the cake and I like how they were small pieces rather than a whole nut. It took longer to blitz the brittle into a smooth paste that I anticipated and I had to keep scraping down the sides of the processor, but the aroma it released while being crushes was unbelievable. Every time I removed the lid of the processor a cloud of deep toasted hazelnut aroma would waft up and smelt so unbelievably good it would almost make me feel lightheaded. It was enough to make you want to weep with happiness.
When it came to assembling the cake all was going to plan. I had lots of praline buttercream leftover and not wanting it to go o waste I decided to use it to cover the top and sides of the cake as well. This worked fine and I put it in the fridge to chill while I made the ganache. When it came to pouring the ganache over the cake I suffered a minor disaster. The ganache flowed and settled on the flat top of the cake fine, but when I tried to smooth it over the sides of the cake it ran off in horrible blotchy patches where it began to melt the butter in the buttercream and run off in oily patches – not good. I piled it all on anyway, stuck it back in the fridge to chill and hoped for the best. When the ganache had cooled but was still spreadable I removed the cake from the fridge and tried to scoop it up the sides of the cake. Thankfully it did stick this time but the end result looked like a monstrosity. Back into the fridge it went and then sufficiently chilled I removed it once again and carefully began to remove the excess ganache from the plate. A few minutes later and ta-da, the cake had been transformed from a blob into something quite presentable – whew! I have learnt a good lesson though, never cover the sides of a cake with buttercream if you want to cover it in a warm glaze :)
When I tasted the finished cake it was well worth the effort and I would definitely consider making it again for a celebration. The hazelnut flavour was gorgeous and all the tastes and textures mingled together well and the smooth dark chocolate ganache finished it off perfectly. The gateau is quite rich so small slices were sufficient.

Be sure to check out the blogroll to see other Daring Bakers creations.

Filbert (Hazelnut) Gateau with Praline Buttercream
From Great Cakes by carol Walter
Hazelnut Genoise

225g toasted skinned hazelnuts
75g plain flour
2 tbsp cornflour
7 egg yolks
55g & 160g caster sugar
1 tsp vanilla extract
½ tsp grated lemon rind
5 egg whites
50g clarified butter, melted

Method
Heat the oven to 180C. Grease and flour a 10inch spring form tin and set to one side. (Use a 6inch tin if halving the recipe)
Place the nuts, flour and cornflour in a food processor and blitz for 30 seconds. Then pulse until you get a fine powdery mixture, but don’t over process. Set aside.
Put the egg yolks into a bowl and whisk for 3-4 minutes until they are light in colour and tripled in volume. Slowly add the 160g of sugar a tablespoon at a time. The mixture should turn moussey and leave a ribbon trail.
Mix in the vanilla and lemon and set aside.
In a clean bowl, whisk the egg whites until soft peaks form. Then add the 55g of sugar a spoonful at a time until glossy.
Pour the egg yolk mixture over the egg whites and whisk until just combined.
Scatter over two tablespoons of the flour nut mixture and fold in gently using a spatula. Continue doing this with the remaining mixture until you have only two tablespoons left. Then drizzle over the clarified butter, add the remaining nutty flour and fold in well.
Pour the batter into the prepared cake tin and bake in the oven for 30-40 minutes until it feels springy to the touch and has started to come away from the sides of the tin.
Leave to cool for 10 minutes before removing from the tin and leaving to cool.

Sugar Syrup
225ml water
55g caster sugar
2 tbsp rum or liqueur of choice

Method
In a small saucepan, heat the water and sugar together until dissolved. Bring the mixture to the boil, then reduce to a simmer and cook for 5 minutes.
Remove from the heat and stir in your liqueur of choice. Set aside.

Swiss Buttercream
4 egg whites
160g caster sugar
300g butter
1 tbsp Grand Marnier or liqueur of choice
1 tsp vanilla extract

Method
Beat the egg whites in a large glass bowl until foamy and nearly at soft peak stage. Then place the bowl over a pan of gently simmering water, but the bowl shouldn’t touch the water.
Whisk the egg whites, adding tablespoons of sugar one at a time. Continue to beat for 2-3 minutes until the sugar has dissolved and the egg whites are warm. The mixture should look like fluffy marshmallow.
Remove the bowl from the heat and beat for 5 minutes until cool.
Place the butter in a clean bowl and beat until soft and fluffy. Continue to beat the butter, adding tablespoons of the meringue mixture until it is all used up.
Beat in the vanilla and liqueur of your choice.
Refrigerate for 10-15 minutes before using.

Praline Paste
150g toasted skinned hazelnuts
150g caster sugar

Method
Scatter the sugar over the bottom of a heavy frying pan and heat over a low flame for 10-20 minutes until the sugar has dissolved and formed a light caramel. Do not stir the sugar, but the odd shake of the pan is ok to enable even melting.
When the sugar has completely melted remove from the heat and stir in the hazelnuts.
Quickly spread the mixture over a baking try lined and greased with parchment paper or a silicone sheet.
Leave to cool before breaking into pieces and blitzing in a food processor to form a paste. This can take up to 10 minutes and you will need to scrape down the sides every so often.
Transfer to a bowl and cover until ready to use, do not put in the fridge.

Praline Buttercream
1 x Swiss buttercream
1 x praline paste
1 tbsp rum or liqueur of choice

Method
Whisk half the buttercream into the praline paste until well combined. Then add the rest of the buttercream and fold in the liqueur of choice.

Ganache Glaze
175g dark chocolate
300g double cream
1 tbsp golden syrup
1 tbsp liqueur of choice
¾ tsp vanilla extract

Method
Chop the chocolate into small pieces and place in a bowl and set to one side.
Heat the cream and the syrup in a small saucepan over a low heat.
Leave it until it just reaches a gentle boil, then remove from the heat and pour over the chocolate.
Stir until smooth and well combined. Stir in the vanilla and liqueur of choice.
Leave to cool and thickened slightly before using, but don’t leave it too long or it will set.

To Assemble
Cut the cake into three even layers and turn the top layer upside down to use as the base.
Brush the layer with some of the sugar syrup and a third of the praline buttercream.
Top with another layer of sponge, moisten with syrup and spread with another third of buttercream.
Top with the final cake layer, moisten with syrup and spread over the rest of the buttercream.
Transfer the cake to a wrack set over a deep baking tray. Brush the sides with a little melted apricot jam and pour over the still soft chocolate ganache glaze. Spreading it out evenly over the top and sides of the cake, catching any excess in the tray below.
Using leftover buttercream or whipped double cream, decorate the top of the cake.
Store in the fridge until required. It can be kept for up to 5 days.