Preheat the oven to 225 degrees F.
Popcorn: Pop the kernels in an air popper, microwave (in which case no oil is required) or on the stove-top. Divide the popped corn between 2 large bowls.
Sweet: Add the brown sugar, corn syrup, salt and butter to a medium saucepan set over medium-high heat. Whisk to blend. Bring the mixture to a boil and cook without stirring until very thick, about 3 minutes. Remove from the heat and immediately add the baking soda, swirling the pan to blend. Pour the caramel over 1 bowl of the popcorn. Toss with 2 spatulas, until the popcorn is fully covered with caramel (do not touch, as the caramel is very hot!). Line a baking sheet with parchment paper (or use a nonstick baking tray). Spread the caramel corn in a single layer over the baking sheet. Bake for 30 minutes, stirring every 10 minutes. When just cool enough to handle, separate the kernels gently with your hands, and allow to cool completely.
Salty: Add the melted butter, cheddar cheese powder and chipotle powder to the second bowl of popcorn. Toss to combine thoroughly. Season with salt..
Mix the caramel and cheese corn together and serve.