Butter a rimmed baking sheet and a rubber spatula, set aside.

Measure all of your ingredients so they are ready to go.

In a large saucepan combine sugar, corn syrup, water and butter. Cook and stir over medium high heat until the mixture starts to boil. Clip a candy thermometer to the side of the pan. Continue to boil and stir occasionally until thermometer reads 315 degrees F.

Remove from heat and add in cashews and stir.

Add in baking soda and vanilla and stir quickly. Immediately pour onto prepared pan. Quickly spread out the mixture with a rubber spatula. Sprinkle with sea salt.

Let cool completely before breaking into pieces. Store in an airtight container for up to 2 weeks.