In a large skillet, add the olive oil over medium-high heat. Add the onions and 1/4 teaspoon each of salt and pepper. Cook, stirring constantly, until the onions begin to soften, about 5 minutes.
Stir in the brown sugar and continue to cook, scraping the browned bits off the bottom of the pan frequently until the onions are golden brown, about 20 minutes. Remove the onions and place on a plate, set aside.
Preheat the oven to 425 degrees F.
In the same skillet you caramelized the onions in, add the chorizo. Now brown the chorizo all over, about 5 minutes. Once the chorizo is browned, add the garlic, jalapeño and chipotle chilies, cook another minute or so. Remove from the heat and stir the onions back in.
Add the cream cheese and cold pack cheddar cheese spread to a microwave safe bowl and microwave for 30 seconds to 1 minute or until the cheese is soft and stir-able. Stir in half of the shredded cheddar, reserving the other half for topping. Stir the warmed cheese mixture into the chorizo/onion mixture until combined.
Either spread the mixture out into an even layer in your skillet (it must be an oven safe skillet) or spoon the mixture into your desired baking dish or dishes and place on a cookie sheet. Top with the remaining shredded cheddar cheese. Bake for 15 to 20 minutes or until hot and bubbly. Remove from the oven and garnish with sliced green onions. Serve with tortillas, bread, or crackers of choice.