Prepare the ramekins

• Brush the ramekins with softened butter, working upwards in vertical strokes.
• Dust with sugar and tap out the excess, then chill.

Melt the chocolate

• Melt the dark chocolate with the butter and hazelnut spread in a saucepan over low heat.
• Stir until smooth, then remove from the heat and let cool slightly.

Make the base

• Whisk the egg yolks into the cooled chocolate mixture.
• Stir in the sifted flour and a pinch of salt until smooth.

Whip the egg whites

• Beat the egg whites with a hand mixer, adding the sugar gradually, until stiff glossy peaks form.

Fold in the egg whites

• Fold a third of the egg whites into the chocolate base to loosen it.
• Gently fold in the remaining egg whites and the crushed hazelnuts, keeping the air in the mixture.

Fill and bake

• Divide the mixture between the prepared ramekins and level the tops.
• Bake at 190 °C until risen and set with a slight wobble in the centre.

Serve

• Dust with sugar and serve immediately, straight from the oven.