Preheat oven to 250 degrees. Spray a large roasting pan with non-stick cooking spray. Combine the popped corn and nuts in the pan, mixing well. Place in the heating oven while preparing the glaze.

In a large saucepan over medium heat, combine the brown sugar, corn syrup, margarine, orange zest and salt. Bring to a boil, stirring constantly until l the sugar dissolves. Boil for 4 minutes without stirring. Remove from the heat and mix in the vanilla and baking soda. Gradually pour the glaze over the popped corn mixture, stirring to coat well.

Bake until dry, stirring occasionally, about 1 hour. Remove from the oven. Using a metal spatula, free the popcorn from the bottom of the pan. Let cool completely in the pan.

Break into clumps. Store in an airtight container at room temperature for up to 1 week.