If you would like to make this for a gift, you may double the recipe. In that case, using a large stockpot will give you ample room to toss the popcorn once the caramel mixture is cooked. For baking the larger quantity, a turkey roasting pan works well.
Make sure to remove any unpopped kernels before mixing in the popcorn
In a large pot (large enough to add the popcorn later and toss), melt the butter over medium heat. Stir in the brown sugar, honey, and salt. Bring to a boil, stirring constantly.
Once the mixture comes to a boil, boil for 4 minutes WITHOUT stirring. I adjust the heat to the lowest possible temperate that will just maintain a boil. This way, the mixture won't burn.
After 4 minutes, remove the pot from the heat and stir in the vanilla and the baking soda. The mixture will get bubbly; this is normal.
Immediately add the popcorn and peanuts. Toss gently but thoroughly. If the mixture starts to firm up before you have thoroughly incorporated the popcorn, place the pot over low heat to soften the caramel mixture and finish mixing.
Place the popcorn mixture in a greased, 9x13 baking dish or other large, shallow pan and bake for 45 minutes, stirring every 15 minutes.
Remove from the oven and turn out onto parchment or wax paper and cool thoroughly, breaking apart any large clumps, if desired.
Store in an airtight container and enjoy!
Notes
If you double the recipe, you may want to bake 15 extra minutes for a total of one hour, stirring every 15 minutes.
When finished, fill the sticky pans with hot water and allow to sit for a few minutes. All the excess caramel mixture will dissolve and cleanup will be a breeze.