Maple fudge recipes call for many of the same ingredients, including maple syrup, sugar, heavy cream and butter. Some recipes substitute milk for the cream, and others add vanilla extract or walnuts. Using brown sugar instead of or in addition to white sugar is another subtle variation on the classic recipe.
In a heavy-bottomed saucepan, combine 2 cups of grade B or dark amber maple syrup, 2 to 4 tablespoons of butter, 1 cup of sugar, and 2/3 to 1 cup of cream or milk. Stir the mixture occasionally, and bring it to a gentle boil until it reaches about 230 F on a candy thermometer. If you do not have a candy thermometer, pour a little bit of the mixture into cold water; it is done when it forms a soft ball.
Remove the fudge from the heat, and add any additional ingredients, such as 1 cup of walnuts or 1 tablespoon of vanilla extract. Stir the fudge until it reaches the desired thickness, about seven to 15 minutes. Use a stand mixer, if you have one available. Once it's thickened, pour the fudge into a buttered or parchment-lined pan. Allow the fudge to set before cutting and serving.