Begin by popping your popcorn in the microwave, removing the unpopped kernels, and pouring the rest into a very large bowl.

Over the stove top on medium-high heat, melt butter. Add marshmallows and orange candy melts and melt completely, while stirring constantly, to avoid burning. Pour over popcorn and quickly and gently toss the mixture with a large spoon to coat all the popcorn. Add in sprinkles, chocolate candies, pretzels, and whatever other options you'd like and gently mix it all together.

Spread and gently pack mixture into a greased 10" bundt cake pan (it will be full) and let it sit for a few minutes until it mostly cools and keeps its shape. Then, carefully turn it over onto a plate or platter to empty the pan. Best when fresh. Keep covered.