In a large bowl, combine the corn muffin mix, corn kernels, creamed corn, sour cream, melted butter, salt, onion powder, garlic powder and chili flakes.
Stir the mixture until everything is well combined. Do not overmix; a few lumps are okay.
Grease a 9x13-inch baking dish or a similar size with cooking spray or a little oil.
Pour the corn mixture into the prepared baking dish and spread it evenly.
Bake in the preheated oven for 35 minutes.
Remove the casserole from the oven and sprinkle the shredded vegan cheddar cheese evenly over the top.
Return to the oven and bake for an additional 10 minutes, or until the cheese is melted and bubbly.
Let the casserole cool for a few minutes before serving. Garnish with chopped green onions if desired.
Notes
If you don't have the corn muffin mix, you can substitute:
2/3 cup (100g) cornmeal
2/3 cup (120g) flour
2 tablespoons sugar
1 tablespoon baking powder
1/2 teaspoon salt
To store: Wrap the leftovers in the baking dish or transfer them to an airtight container; refrigerate for up to 4 days. Reheat in a 350ºF oven until the corn casserole is completely warmed through, or heat it up in the microwave.
To freeze: Corn casserole can be frozen for up to 3 months. Use freezer-safe containers or wrap the casserole tightly in the baking dish. When ready to enjoy again, thaw it in the refrigerator overnight before reheating in the oven or microwave according to the instructions above.