(edited very slightly from the original at An Edible Mosaic)
12 cups air-popped popcorn (1/2 cup popcorn kernels)
1 cup walnuts
1/2 teaspoon baking soda
1 teaspoon cinnamon
1 teaspoon ginger
1/2 teaspoon nutmeg
1/4 teaspoon cloves
1/2 cup (1 stick) unsalted butter
1 cup light brown sugar, lightly packed
2 tablespoons molasses
1 tablespoon water
1 teaspoon pure vanilla extract
1. Get everything prepped. Mix the popcorn and nuts in a very large bowl, and set aside. Line a large baking sheet with parchment paper and set aside. Mix together the baking soda, cinnamon, ginger, nutmeg, and cloves in a small bowl and set aside.
2. Cook the butter, sugar, molasses, water, and salt in a medium-sized, thick-bottomed saucepan over medium heat until it boils, stirring occasionally. Continue to let it boil, stirring constantly, for three minutes. Carefully stir in the vanilla and baking soda/spice mix, and pour over the popcorn/nut mixture.