This is a moist, quite dense cake, with the hazelnuts and Toblerone giving it a crunchy texture. It's not richly chocolatey, as the Toblerone is milk chocolate, but it's a pleasant cake for everyday eating.
Here's the recipe:
170g plain flour
1/2 teaspoon salt
2 teaspoons baking powder
200g caster sugar
Measure the above ingredients into a large bowl, and whisk together with a ballon whisk. You can sift the flour and cocoa if you prefer, but I don't find it necessary.
250g wholemilk natural yogurt*
100g sunflower oil*
3 large eggs
1 teaspoon vanilla extract
*I find it simpler to weigh the oil and yogurt, rather than move them in and out of measuring jugs.
Mix the wet ingredients in a bowl or jug, then pour onto the flour mixture, and beat for a couple of minutes until the batter is smooth and well blended. Fold in the chosen flavouring ingredients, in this case:
100g Toblerone (milk with honeycomb crisp), chopped quite small
50g finely chopped hazelnuts
Transfer the batter to a prepared 20cm diameter springform cake tin, base lined with baking parchment, and bake at 180C for about 60 minutes, or until a test probe comes out clean.
Cool for 15 minutes in the tin before removing the cake to a wire rack.