Prepare Your Cooking Pot: Select a large, heavy-bottomed pot with a tight-fitting lid to ensure even heat distribution and prevent popcorn from escaping. Pour in the vegetable or canola oil, spreading it evenly across the bottom in a thin layer.
Add Popcorn Kernels: Place the popcorn kernels into the pot so they form a single layer. This helps the kernels pop uniformly without overcrowding, which can lead to uneven cooking.
Heat and Pop the Corn: Cover the pot with the lid and place it over medium-high heat. As the kernels heat up, they will begin to pop. Gently shake the pot every 15-20 seconds to prevent the kernels from burning and to help unpopped kernels settle to the bottom. Listen for the popping to slow down significantly—when there are about 2 seconds between pops, it's time to remove the pot from heat. Mix the Spice Blend: While the popcorn is popping, combine chili powder, paprika, garlic powder, rosemary, salt, pepper, and cayenne pepper in a small bowl. This mixture will add a bold, spicy flavor to the popcorn.
Season the Popcorn: Once the popcorn is fully popped, immediately drizzle the melted butter over the hot kernels. Sprinkle on your desired amount of the prepared spice mix and toss thoroughly in a large bowl to ensure every kernel is coated evenly.
Add Parmesan Cheese: Grate fresh Parmesan cheese directly over the seasoned popcorn. Toss once again gently to distribute the cheese evenly, giving the popcorn a savory, cheesy finish.
Serve Immediately: Transfer the popcorn to serving bowls and enjoy while warm for the best texture and flavor.