In a large heavy-bottomed saucepan, bring the maple syrup to a boil over medium-high heat stirring occasionally. Boil until syrup reaches 235 degrees F (110 degrees C) on a candy thermometer.
Remove from heat and cool to 175 degrees F (80 degrees C) without stirring, about 10 minutes.
Stir mixture rapidly with a wooden spoon for about 5 minutes until the color turns lighter and mixture becomes thick and creamy. Stir in chopped nuts, if desired.
Pour into molds. Set aside to cool. Once cool, unmold candy. Store in airtight containers up to 1 month.
