
Line a baking sheet with a silicone mat or parchment paper lightly spritzed with baking spray.
Separate the egg whites and transfer to the bowl of a stand mixer fitted with a whisk attachment.
In a medium pot, stir to combine the sugar, water, salt, and corn syrup and place over medium heat. Once the mixture comes to a boil, stop stirring and use your candy thermometer to keep track of the heat. Remove the pot from heat immediately when it reaches 255°F. When the sugar mixture nears 230°F, beat the egg whites on high speed to stiff peaks.
As soon as the sugar mixture reaches 255°F, remove it from the heat and slowly drizzle it into the egg whites while the mixer runs on high. This will take a few minutes as you will be drizzling a thin stream into the egg whites.
Beat for 4-5 minutes or until the glossy appearance starts to fade. Spoon a test portion onto the baking sheet and see if it holds its shape.
Immediately mix in the vanilla and pecans then turn mixer off and use two spoons to portion out 1-2 tablespoon-sized pieces onto a parchment or silicone-lined baking sheet. Allow to set before storing in an airtight container.