First Step: Prepare the popcorn Pop 10 cups of popcorn using your preferred method, ensuring to remove all unpopped kernels. Transfer to a large mixing bowl. Add extra popped popcorn if you want lighter, fluffier balls.

Second Step: Make the caramel sauce Choose between two methods: * Microwave Method: Combine ½ cup butter, 1 cup packed brown sugar, and ¼ cup light corn syrup in a microwave-safe bowl. Microwave on high for 1 minute, stir, then microwave for an additional 2-3 minutes until the mixture is bubbly and caramel-colored. * Stovetop Method: Combine 1 cup brown sugar, ¼ cup corn syrup, 1 cup water, 1 cup white sugar, 2 teaspoons white vinegar, and a pinch of salt in a saucepan. Bring to a boil over medium-high heat, stirring frequently. Continue boiling until a small amount dropped into cold water forms a hard ball (250°F on a candy thermometer). Remove from heat and stir in ½ cup butter until melted.

Third Step: Add final flavorings Immediately remove the caramel from heat (or microwave), then stir in 1 teaspoon vanilla extract and ½ teaspoon baking soda. The baking soda will cause the caramel to foam, creating a lighter, airy texture.

Fourth Step: Combine caramel and popcorn Pour the warm caramel sauce over the popcorn. Toss gently and thoroughly with a spatula or wooden spoon to evenly coat all the popcorn. If desired, fold in optional mix-ins like nuts, candy pieces, or chocolate chips while the caramel is still warm.

Fifth Step: Shape the popcorn balls Allow the coated popcorn mixture to cool slightly until it is warm but safe to handle. Grease your hands with butter or a neutral oil to prevent sticking. Shape the mixture into round balls about 2 to 3 inches in diameter. For easier shaping, you can spoon the mixture into muffin tins.

Final Step: Set and store Place the formed popcorn balls on wax paper or a lined tray and let them cool completely at room temperature until firm. Store the caramel popcorn balls in an airtight container, wrapped individually or in layers, at room temperature. They will remain fresh for up to two weeks.