• NOTE: This is not an activity for children, nor should children be nearby. The mixture becomes extremely hot and can blister skin with just a small splash.

Toast Walnuts

• Add walnuts to a dry skillet over medium-high heat.
• Stir constantly until walnuts are fragrant and beginning to brown.
• Immediately scoop from the skillet onto a plate to cool. Set aside.

Brittle

• Line a baking sheet with parchment paper and set aside.
• Place a heavy-bottomed saucepan over medium heat
• Pour in maple syrup, white sugar, butter, and water and stir until melted and creamy.
• Once the mixture comes to a boil, discontinue stirring. May gently swirl the mixture in the pan if needed.  
• Attach a candy thermometer to the saucepan and continue to gently boil until the candy thermometer reaches 300°F or "hard crack" stage.
• Immediately stir in walnuts until well coated.
• Carefully pour the hot brittle mixture onto the prepared baking sheet. Use a wooden spoon to spread to a thin layer.
• Sprinkle top with coarse sea salt and allow to cool completely. Break into large pieces and store in an airtight container.