A great gift or perfect for just enjoying any time. Like all brittles, this needs to be boiled to the "hard crack" stage, which is 300 degrees F. You will need a candy thermometer to measure most accurately. Always be super careful when working with really hot sugar mixtures!
1/4cupreal maple syrup
1cupgranulated white sugar
1cupbuttercut into chunks
Coarse salt such as Maldon or Fleur de sel(optional)
Toast the walnuts: Add walnuts to a dry skillet over medium-high heat. Cook, stirring constantly, until walnuts are fragrant and beginning to brown. Immediately remove from the skillet to a plate to cool. Set aside.
Line a baking sheet with parchment paper and set aside.
For the brittle: In heavy bottomed saucepan over medium heat, stir together the maple syrup, white sugar, butter, and water until melted and creamy. Once mixture comes to a boil, do not stir any more (you can gently swirl the pan, if you feel it needs it). Attach a candy thermometer to the saucepan and continue to gently boil until candy thermometer reaches 300°F or "hard crack" stage. Immediately stir in walnuts until well coated.
(*Do be careful when working with this very hot sugar mixture. Even the smallest splash on your skin can blister it. Definitely not an activity for kids or even having them any where close by to the boiling mixture). Very carefully pour the hot brittle mixture onto the prepared baking sheet and spread out to a thin layer with a wooden spoon. Sprinkle top with a bit of coarse salt, such as Maldon or Fleur de Sel, if desired.
Allow to cool completely. Break into large pieces and store in an airtight container.
Be sure to read the "Cook's Notes" in the original post, for more tips, options, substitutions and variations for this recipe!