Heat ¼ cup coconut oil or vegan butter in a large pot over medium heat. Add ½ cup popcorn kernels, cover slightly ajar, and shake occasionally for 3-5 minutes until popping slows. Transfer to a mixing bowl.

In a separate saucepan, melt 2 cups mini marshmallows over low heat, stirring gently for 3-4 minutes until smooth. Pour over the popcorn.

Melt 1 cup candy melts in a microwave-safe bowl, about 30 seconds at a time until smooth. Drizzle over marshmallow-coated popcorn and mix gently.

Sprinkle ½ cup colorful sprinkles over the popcorn mixture and add chopped nuts if desired. Fold together with a spatula.

Spread the mixture onto a parchment-lined baking sheet and let cool for 15-20 minutes to firm up.

Once cool, break into clusters and place in bowls, jars, or gift bags for sharing.