Grease and line a 20cm (8inch x 8inch) square baking pan with non-stick parchment paper. Let the paper extend over the edges so the fudge is easy to remove later.
Place all of the ingredients in a heavy based saucepan and gently heat over low heat. Stir regularly until the chocolate buttons melt thoroughly and the mixture starts to thicken. Do not overheat or the chocolate may burn.
Pour the mixture into the prepared tin, smoothing the top to make a neat finish. Place the tin in the fridge for at least 3 hours.
Remove fudge from the fridge and slice into squares with a sharp knife. We cut our fudge into 36 small squares, but you might prefer to make finger shaped slices.
Notes
Prepared fudge keeps best in the fridge to stop melting. It will keep in the fridge for a few weeks. Fudge can also be kept in the freezer for up to 3 months. Place your fudge pieces between sheets of non-stick parchment paper before freezing to prevent sticking and store in an air tight bag or container.