For the cake layers
- 350 g butter, at room temperature
- 300 g granulated sugar
- 450 g self-rising flour
- 4 eggs, medium
- 300 g strained yogurt
- 1 teaspoon(s) vanilla extract
- orange zest, of 1 orange
- 1 tablespoon(s) baking powder
- 1 pinch salt
For the caramelized hazelnuts
- 100 g granulated sugar
- 50 g water
- 200 g hazelnuts
For the Swiss buttercream
- 4 egg whites, from medium eggs
- 220 g icing sugar
- 1 pinch salt
- 250 g chocolate couverture, melted
- 380 g butter, at room temperature
To serve
- hazelnuts, caramelized