Pop the Popcorn: Start by popping your popcorn, making sure to remove any unpopped kernels. Place the popped popcorn in a large mixing bowl. If desired, you can use black and orange food coloring on half and half of the popcorn to create a festive Halloween look.

Prepare the Caramel Sauce: In a medium saucepan, melt the butter over medium heat. Once melted, stir in the brown sugar, corn syrup, salt, and cream of tartar. Continue to stir until the mixture comes to a boil.

Boil the Mixture: Allow the mixture to boil without stirring for 5 minutes. Keep an eye on it to ensure it doesn't burn.

Add Baking Soda and Vanilla: Remove the saucepan from the heat and quickly stir in the baking soda and vanilla extract. The mixture will bubble up, so be cautious.

Coat the Popcorn: Immediately pour the caramel sauce over the popped popcorn, stirring to ensure every kernel is coated evenly.

Bake the Caramel Corn: Preheat your oven to 250°F (120°C). Spread the caramel-coated popcorn on a large baking sheet lined with parchment paper. Bake for 1 hour, stirring every 15 minutes to prevent burning.

Add Halloween Decorations: Once the caramel corn has finished baking, remove it from the oven and let it cool slightly. While still a bit warm, sprinkle in the candy eyeballs, gummy worms, and any other creepy Halloween decorations.

Cool Completely: Let the caramel corn cool completely to room temperature before serving. This allows the caramel to harden and set properly.