Add the corn syrup, SunButter, brown sugar, and butter to a medium saucepan over medium heat. Stir until combined and smooth, then continue to cook for 3 minutes, stirring frequently. Remove the caramel from the heat, then add the salt, vanilla, and baking soda to it. Stir to combine.
Add popped popcorn and pretzels to a baking sheet. Pour SunButter caramel over top, then mix and toss well until all of the popcorn is coated.
Bake the caramel popcorn in the oven for 30 minutes, ensuring that you mix and toss again halfway through baking.
After the popcorn is finished baking, allow to cool for 10 minutes, then add chocolate chips and toss lightly. Consume warm or wait to cool to room temperature. Store in a sealed ziploc bag.