Preheat the oven to 325 degrees F and line a baking sheet with parchment paper. Heat 3 popcorn kernels and the vegetable oil in a large saucepan over medium heat until 1 kernel pops; add the remaining kernels, cover and cook, shaking the pan occasionally, until the popping subsides. Remove from the heat and transfer to a large bowl.
Add the cereal, crackers, pretzels and almonds; toss to combine. Melt the butter in a small saucepan over low heat. Stir in the chili powder, paprika and garlic powder. Drizzle over the popcorn mixture and toss with a rubber spatula to coat; season with salt.
Spread the snack mix on the prepared baking sheet. Bake, stirring once or twice, until lightly toasted, about 10 minutes. Let cool completely. Store in an airtight container for up to 5 days.