Preheat the oven to 180C / 350F / 160C fan forced and set aside a 4x10 inch rectangular tart tin.
Sift together the flour, cocoa, baking powder and salt in a large bowl, then add the hazelnut meal and two sugars. Mix well.
Add the melted butter and stir gently, then mix in the eggs, chopped hazelnuts and vanilla. Mix it all together with a spoon until well combined.
Pour the chocolate fudge batter into the baking tin and spread it out evenly. Bake for around 20 minutes until almost done (a toothpick should come out still a bit sticky). Allow it to cool completely in the tin.
For the hazelnut buttercream
Melt the white chocolate, then allow it to cool a little while you get on with the buttercream
Use a blender to grind the toasted hazelnuts as fine as you can
Beat the butter and icing sugar together until light and creamy. Add the vanilla and cream. Use a sieve to sift the ground hazelnuts over the butter mixture, pushing through what you can, then discard the larger pieces. Beat well.
Add the cooled white chocolate and beat on medium-high for 3 minutes until it looks whipped and creamy.
Spread of pipe the hazelnut cream over the top of the brownie
Top with extra hazelnuts and grated chocolate
I use a standard Australian 20ml tablespoon (4 teaspooons worldwide)
For best results you should always weigh ingredients like flour and sugar. Kitchen scales are relatively cheap but if you can’t weigh the ingredients, use the spoon and level method (don’t scoop).
TOOLS USE IN THIS RECIPE
A handheld beater
A simple silicone spatula so nothing gets left behind