Begin by popping 10 cups of plain popcorn using your preferred method, whether stovetop or microwave. Remove unpopped kernels.

While the popcorn is still warm, sprinkle salt liberally over it to enhance the flavor and toss gently.

In a medium saucepan, melt 1 cup of sweet cream salted butter over medium-low heat. Stir in 1 cup of light brown sugar until well combined and slightly bubbly.

Bring the butter and brown sugar mixture to a boil without stirring for 4 minutes, watching closely to avoid burning.

Remove saucepan from heat, stir in 2 teaspoons of pure vanilla extract and mix in ½ teaspoon of baking soda; the mixture will foam up.

Pour one-third of the caramel sauce over the salted popcorn and gently fold until coated. Gradually add remaining caramel in batches.

Stir in the chopped Rolo candies, Pretzel M&M's, and regular M&M’s into the caramel-coated popcorn mixture.

Transfer the mixture onto a lined cookie sheet, spreading it out evenly. Allow it to cool at room temperature for about 30 minutes.