Name: Triple hazelnut cake with chocolate buttercream icing
Prep time: 75 min
Cook time: 45 min
Yield: 8
Cuisine: American
Ingredients: For the cake; Shortening, for greasing tins; 2 tbsp plain flour, plus 500g; 4 large eggs, at room temperature, lightly beaten; 80ml hazelnut-flavoured liqueur; 1 tsp hazelnut essence; 395g granulated sugar; 1 tsp baking powder; 1 tsp bicarbonate of soda; 1 tsp fine-grain sea salt; 175g peeled, toasted and finely chopped or ground hazelnuts; 330g unsalted butter, at room temperature; 240ml sour cream, at room temperature; For the hazelnut filling; 4 tbsp unsalted butter, at room temperature; 4 tbsp plain flour; 225g granulated sugar; 240ml whipping cream; 175g peeled, toasted and finely chopped hazelnuts; 1/4 tsp fine-grain sea salt; 1 tbsp hazelnut-flavoured liqueur; 1 tsp hazelnut essence; 2 tbsp finely chopped plain chocolate or chocolate disks; For the chocolate buttercream icing; 225g plain chocolate, finely chopped, or chocolate disks; 225g granulated sugar; Egg whites from 7 large eggs, at room temperature; 440g unsalted butter, at room temperature; 1 tsp hazelnut essence; For the garnishes