- Grease a loaf pan with butter, line the pan with parchment paper, leaving a bit of an overhang on both the long sides.
- In a saucepan, bring the maple syrup to a boil over medium heat; simmer for 5 minutes. Keep a very close eye on the syrup, it will rise quite a lot.
- After 5 minutes, pour in the heavy cream. Without stirring bring the mixture back to the boil and then let it simmer until it reaches 236°F on a candy thermometer, which should take about 20 minutes.
- When the mixture reaches temperature, remove the pan from heat. Add butter to the pot but do not stir it in. Let the mixture cool for 8 minutes
- Beat with an electric mixer on medium speed for about 5 minutes, until the sugar mixture gets thicker, lighter, loses its sheen, and starts to show signs of crystallization.
- Promptly transfer the fudge to the prepared pan; spread all the way to the edge and transfer to the fridge until completely set, about 2 to 3 hours.
- Remove from the pan, cut into pieces, and enjoy!