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.
Notes
A note about the weather: If possible, make this easy divinity candy recipe on a day with low humidity. High humidity can affect how the divinity sets and make the outside sticky instead of firm.
You'll need to use a stand mixer to make this. Motors in handheld electric mixers tend to be much weaker and since this is a very thick and sticky consistency, a hand mixer will probably struggle.
A reliable candy thermometer is a must. It's essential that the sugar reaches the correct temperature or the candy might not set properly.
Timing tip: Wait until the sugar has reached 230°F to whip the egg whites. You want the sugar mixture and egg whites to be ready at the same time.
Work quickly once the candy is ready. Make sure to have your silicone mat, wax paper, or parchment-lined baking tray ready before starting. You have to work quickly to avoid the candy setting in the bowl.