Grease and line an 8 inch (20cm) square baking pan with baking/parchment paper. Allow an overhang of the baking paper for ease of removal.
Melt the chocolate: The chocolate can be melted either on the stove top OR in the microwave see note 3
Add in the Nutella: Remove the bowl of melted chocolate from the microwave or stovetop and add in the Nutella. Use a rubber spatula or whisk to combine the two ingredients.
Once well combined, pour the mixture into the prepared lined baking pan.
Tilt the pan to distribute the mixture evenly. Smooth out the surface by gently shaking the pan which will remove bubbles and ridges.
Refrigerate or freeze: Refrigerate for about 40 minutes or until the fudge is firm see note 4
Remove from refrigerator: Once the fudge has set, remove it from the freezer or fridge. Using the overhang of parchment paper gently lift out the set fudge and place it onto a board.
Slice into serving portions: Dip a sharp knife into a glass of warm (not hot) water, wipe dry then slice the fudge into portion sizes you prefer. Repeat before cutting each slice. The knife should not be too hot, just warm or the chocolate will melt as you slice into the fudge.