Preheat your oven to 170C/340F. Grease and line the base of a 10in springform cake tin and set aside.

Place a heatproof bowl over a small saucepan of simmering water, ensuring that the water does not touch the bowl. Add the butter and chocolate.

Heat, stirring often, until the mixture is about 80% melted, then remove from the heat and set aside to cool slightly.

Place the eggs into a large mixing bowl and use a hand mixer with a whisk attachment on high speed until the eggs are fluffy and have doubled in size.

Add a cup-full of the egg mixture into the chocolate and fold together to help the mixtures combine, then pour the chocolate mixture into the eggs.

Fold the chocolate and eggs together until you have a thick, smooth batter.

Pour the batter into your prepared tin.

Bake for 30-45 minutes, until the center of the cake only jiggles slightly when moved. The cake will sink a little in the center as it cools.

Leave to cool in the pan for 20 minutes before turning out onto a serving plate.

Once completely cooled, dust with powdered erythritol, cut into slices and serve.