1-Gathering and Prepping Ingredients: First, make sure you have all ingredients measured out for efficiency. Pop the popcorn ahead and set it aside to keep things organized. This preparation helps avoid any last-minute rush and ensures even coating later on.

2-Cooking the Caramel: Preheat the oven to 200°F (93°C) and line one or two 12×17-inch baking sheets with silicone mats or parchment paper. Place the popcorn in a large bowl or spread it evenly on the prepared baking sheets. In a medium saucepan over medium heat, combine the brown sugar, corn syrup, butter, salt, and cream of tartar, stirring constantly until the butter has melted and the mixture begins to simmer.

3-Cooking the Caramel: Allow the mixture to boil without stirring for 4 minutes, until it reaches 234 235°F (112 113°C). Remove from heat and immediately stir in the baking soda; the mixture will bubble and become frothy. This step is crucial for that airy texture you want in the finished product.

4-Coating and Baking: Pour the caramel over the popcorn and gently stir with a large spoon or spatula to coat all the popcorn evenly, then spread the coated popcorn evenly on the prepared baking sheets. Bake for 1 hour, stirring every 20 minutes to ensure even coating. Let cool on the baking sheet for at least 30 minutes until the caramel hardens, then break apart any large clusters.