How to make it:

Make the stovetop popcorn:
Place a large (8-quart) saucepan over high heat and add the oil. The oil should just cover the bottom of the pan. Heat the oil until it's rippling but not smoking, then add the popcorn kernels and shake the pot so the kernels form a single layer on the bottom.

Place the lid on the pan and immediately reduce the heat to medium. Once the kernels start popping, shake the pan every so often and listen to the pace of the popping: The kernels should pop rapid-fire in one long continuous burst. As soon as the popping slows to a few kernels at a time, turn off the heat and remove to a cool burner.

Remove any unpopped ones and place popcorn in a large mixing bowl. Set aside.

Melt the marshmallows:
In a large saucepan over low heat, melt the butter. Add the marshmallows and stir until fully melted and smooth. Remove from heat and stir in vanilla extract (and salt, if using).

Pour the marshmallow mixture over the popcorn. Use a spatula (lightly greased to prevent sticking) to gently fold and coat all the popcorn.

For popcorn clusters or balls, lightly grease your hands and shape immediately, setting aside to slightly cool and harden on a parchment paper.

Add sprinkles or drizzle with chocolate for extra flair.