Preheat oven to 250 degrees.
Place popcorn and chopped pecans in a large bowl and set aside.
Combine brown sugar and cinnamon in a 2 liter capacity microwave safe bowl. Mix well. Chop butter into chunks and place on top of sugar mixture. Pour corn syrup over the top of everything. Microwave on high for 30 seconds and then stir to combine. Return to microwave and heat for 2 minutes. Remove and stir and then microwave for 2 minutes more.
Remove from microwave and add in vanilla and baking soda. Stir to combine. Mixture will foam and rise. Pour caramel mixture over popcorn and pecans and stir very well so everything is well coated.
Spread popcorn mixture onto a foil-lined jelly roll pan. Place in oven and bake for 30 minutes, stirring every 10 minutes.
Remove from oven and spread out on a large piece of parchment, waxed paper, or foil.
Melt almond bark according to package instructions. Drizzle over popcorn mixture. When almond bark is hardened and popcorn is cool, break into chunks and enjoy!