Line a baking sheet with parchment paper; lightly spray with cooking spray.
In a large stainless steel saucepan, stir together sugar, corn syrup, ½ cup water, and salt just until sugar is moistened. Cook over medium-high heat, without stirring, until a candy thermometer registers 260°, 10 to 12 minutes. When thermometer registers near 240°, continue to next step.
In the bowl of a stand mixer fitted with the whisk attachment, beat egg whites and cream of tartar at high speed until stiff peaks form. When sugar mixture has reached 260°, with mixer on low speed, slowly pour sugar mixture into egg white mixture in a slow, steady stream. Beat at high speed until mixture holds its shape and begins to lose its gloss, 6 to 9 minutes. Immediately reduce mixer speed to low, and add chopped pecans, orange zest, and vanilla, beating just until combined.
Working quickly with 2 spoons or a small spring-loaded scoop, immediately drop mixture by tablespoonfuls onto prepared pan. Gently press a pecan half on top of each. Let stand until dry and can easily be removed from pan, about 6 hours. Store in an airtight container for up to 2 weeks.
Notes
KITCHEN TIP Be sure to let candy dry before storing.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/classic-christmas-divinity/