Line 1 large, rimmed baking sheet with nonstick aluminum foil or parchment paper; set aside. Combine popcorn and almonds in a very large bowl; set aside.
Combine butter, corn syrup, and brown sugar in a large (3-quart), heavy pan. Cook over medium-low heat, stirring often, until butter melts and sugar dissolves. Increase heat to medium, and bring to a boil. Cook, without stirring, until mixture reaches 254° (very hard ball) on a candy thermometer. Remove from heat.
Stir in salt, baking soda, and vanilla extract. (Mixture will bubble.) Quickly pour mixture over popcorn and nuts; toss gently to coat. Transfer popcorn mixture to prepared baking sheet.
Bake at 250° for 45 minutes, stirring occasionally. Remove from oven; cool completely. Store in an airtight container for up to 2 weeks.
Love this recipe! But not writing this review to just say that. Felt the need to point out to diabeticsnacker that margarine has virtually the same number of calories as butter ( 1 c margarine = 810 calories; 1 c butter = 812 calories). The only difference is it's source, not calories.
And as for Splenda ... to take advantage of the reduction in calories, you need to use 1/2 the amount of brown sugar in the original recipe. If you did that, then you took out approximately 356 calories (1 c brown sugar = 836 vs 1/2 c Splenda = 480). If not, and you used equal amounts which I find most people tend to do because they think it's less in calories than sugar, you 've actually increased the calories: 1 c of Splenda = 960 calories vs 1 c of regular brown sugar = 836 calories.
It's delicious but you'll need a dentist in the family if you make it! I swap out
splenda for the sugar at least & use lower fat margarine for the butter. I also do
a double of the amount of popcorn kernels so it's not as bad as it could be for you.