Line a cookie sheet with parchment paper or a silicone baking mat and set it aside.

In a large saucepan over medium heat, combine the sugar, water, corn syrup, and a pinch of salt. Stir occasionally until the mixture starts to boil.

Attach a candy thermometer to the side of the pan and continue to cook without stirring until the temperature reaches 260 degrees F (about 8-10 minutes).

While the sugar mixture is cooking, beat the egg whites on high speed using a stand mixer with a whisk attachment until stiff peaks form. Then, switch to the paddle attachment.

Once the sugar mixture reaches 260 degrees F, remove it from heat and very slowly pour it in a thin, steady stream over the egg whites while mixing on high speed. It should take about 2 minutes to pour the hot liquid over the egg whites.

Continue to beat on high speed for another 5-8 minutes until the candy loses some of its glossiness and starts to hold its shape. Test a small amount of candy by dropping a spoonful onto the parchment paper. It should hold its shape in a nice mound with swirls on top.

Mix in the vanilla extract and chopped walnuts when the candy holds its shape. Using two spoons sprayed lightly with cooking spray, drop tablespoon-sized scoops of divinity onto the prepared baking sheet, using one spoon to scrape the hot candy off the other spoon. Work quickly while the candy is still hot.

Let the divinity set at room temperature until firm. Once set, store the divinity in an airtight container for up to 5 days.