Preheat oven to 190°C and line a 20cm round tin with baking paper.

Place chocolate, butter and sugar into a medium size glass bowl and melt in the microwave for 3 minutes checking halfway and stirring. Don't be concerned if the sugar doesn't fully dissolve. As long as the butter and sugar have melted.

Add the flour, salt and eggs and mix using a hand whisk until mixture is smooth.

Pour into prepared cake tin and bake for 20-30 minutes or until the edges have come away from the sides of the tin. Insert a skewer and ensure it comes out almost clean.