Line a large baking sheet with parchment and set aside.
Melt the white candy coating in a microwave-safe bowl in 30-second bursts, stirring after each. Stir in oil if needed until smooth.
Add the puffed corn to a very large bowl.
Pour the melted coating over the puffcorn and gently toss with a spatula until evenly covered.
Spread the coated puffcorn onto the prepared sheet in an even layer.
While still tacky, sprinkle on mini candies, crushed peppermint, sprinkles, and a light shower of sea salt.
Let set at room temperature until firm, about 15 minutes, then break into clusters and serve.