1. Pour corn kernels into the air popcorn machine as the picture shown.
2. Put the hood, cover the top lid and connect the power. Let the machine run and a couple minutes later popcorn will come out.
3. Using a big bowl to hold the air popped popcorn.
4. Put a piece of parchment paper on the tray. (Big enough to cover the tray.)
5. After that, put the popped popcorn on the tray and spread them. Then, preheat the oven for 200 F.
6. Add butter into a non-stick pan or pot. Then, turn on the fire to medium low. Let the butter melt.
7. Next, add light brown sugar. Mix the butter and brown sugar.
8. The following step, add salt and light corn syrup. Continue to stir it until sugar melts.
9. Then, add cream of tartar and baking soda. Mix it well.
10. Pour the caramel syrup from step 9 over the popped popcorn on the cookie sheet step 5 and mix it well.
11. Mix the popcorn and caramel syrup well and make sure every popcorn is coated with caramel syrup.
12. When the oven reaches to 200 F, put them into an oven and bake for 1 hour at 200 F. Take it out every 20 minutes and mix it. Total repeat this step for 3 times.