Preheat the oven to 180°C (fan 160°C)/350°F/ gas mark 4. Line a 6-hole deep muffin tin with paper muffin cases. Gently melt the chocolate and chocolate spread together in a heatproof bowl set over a saucepan of barely simmering water, making sure the surface of the water does not touch the bowl. Leave to cool for a few minutes.
Sift the flour, baking powder and cocoa powder into a large bowl, then stir in the sugar. In a separate bowl, beat the eggs, vanilla, oil and milk together using an electric hand whisk. When combined, stir in the cooled chocolate. Fold the wet ingredients into the dry ingredients using a rubber spatula or metal spoon, but don’t over-mix. Stir in the chocolate chips.
Divide the mixture between the muffin cases, filling them three-quarters full, then sprinkle the hazelnuts over the tops. Bake in the oven for 20–25 minutes, or until a skewer inserted into the centres comes out clean. When cooked, transfer to a cooling rack to cool. Tip: This recipe will make 12 small cakes if you use a shallow bun tin.
Recipe from Chocolat (to be released in June 2013) by Eric Lanlard, published by Mitchell Beazley with photography by Kate Whitaker.