4 tablespoons unsalted butter, cut into small pieces, plus more for coating the bowl and your hands
3/4 teaspoon fresh ground nutmeg
1 teaspoon vanilla extract
1/2 cup dry roasted almonds, coarsely chopped
Coat a large heatproof bowl with butter or nonstick cooking spray and place the popcorn in the bowl. Set aside.
Place the sugar, corn syrup, water, vinegar, and salt in a medium saucepan and stir to combine. Place over medium-high heat, stirring until the sugar has dissolved, about 2 minutes. Bring to a boil and cook until the mixture registers 260°F on a candy/fat thermometer, about 5 to 7 minutes.
Remove from the heat and stir in the butter, nutmeg, and vanilla until melted and smooth.
Immediately drizzle the sugar mixture over the popcorn. Add the almonds and stir continuously with a rubber spatula, scraping the bottom of the bowl, until the popcorn is thoroughly coated and cool enough to handle, about 3 minutes.
Using buttered or oiled hands, tightly press the mixture (it may still be a bit warm) into 3-inch rounds. Place on waxed or parchment paper to cool completely, about 15 to 20 minutes.
Wrap individually and store at room temperature until ready to eat or gift.