- Line the bottom of an 8-inch (20 cm) square pan with parchment paper, letting the paper hang over two sides. Butter the other two sides.
- In a heavy saucepan, bring all the ingredients except for the chocolate and vanilla to a boil, stirring until the sugar is dissolved. Let simmer without stirring until a candy thermometer placed into the centre of the pan reads 240°F (115°C). Remove from the heat and add the chocolate and vanilla without stirring.
- Place the pan in a water bath. Let cool without stirring for 20 to 30 minutes or until the thermometer reads 110°F (43°C).
- Remove the pan from the water. With an electric mixer, beat the mixture for about 2 minutes or until it is thick and loses its gloss.
- Immediately pour into the prepared pan and spread with a spatula. Cover with plastic wrap and let cool for 1 hour at room temperature or 30 minutes in the refrigerator. Unmould and cut into 1-inch (2.5 cm) squares.
- Store in an airtight container. The fudge squares can be made in advance and freeze very well.
Adding white chocolate to your maple fudge is the secret to creamy texture; it does not change the flavour. Just a small 1 oz (28 g) piece will do.