Instructions

Whisk 6 large eggs plus 2 large yolks, ½ cup plus 2 tablespoons sugar, and ¼ teaspoon table salt in medium bowl until thoroughly combined, about 30 seconds. Bring 32 ounces whole milk to simmer in large saucepan over medium-high heat, stirring occasionally.
When milk comes to simmer, remove from heat and, whisking constantly, slowly pour into egg mixture to temper. Return milk-egg mixture to saucepan. Place over medium-low heat and cook, stirring constantly with spatula, until mixture reaches 160 degrees, 2 to 5 minutes.
Immediately pour custard through fine-mesh strainer into large bowl. Whisk in 8 ounces bourbon, ¾ cup canned unsweetened pumpkin puree, 1 teaspoon vanilla extract, ¾ teaspoon ground cinnamon, ¼ teaspoon ground allspice, ¼ teaspoon ground ginger, and ¼ teaspoon freshly grated nutmeg. Cover and refrigerate until base registers 40 degrees, at least 3 hours or up to 3 days. (Alternatively, base can be chilled to 40 degrees in about 1½ hours by placing bowl in ice bath filled with 6 cups ice, 1⁄2 cup water, and 1⁄3 cup table salt.)
Vigorously whisk 4 ounces chilled heavy cream in separate chilled bowl until soft peaks just begin to form, about 60 seconds. Whisk whipped cream into chilled eggnog until fully incorporated. Serve in chilled punch cups, garnishing individual portions with extra cinnamon and nutmeg.