Melt the cream cheese and heavy cream in the microwave until the mixture can be stirred easily, then transfer to a large mixing bowl.
Mix cumin, garlic powder, paprika, salt, and pepper in a separate bowl and add to the cream cheese mixture.
Add shredded cheddar cheese, salsa, and chili to the mixing bowl and whisk until all ingredients are mixed. Taste and add more salt and pepper to suit your preference.
Pour the mixture into the baking dish and smooth into an even layer. Sprinkle the remaining shredded cheese.
Transfer the baking dish to the oven and bake until the dip is bubbly and slightly browned. Optionally, broil for 1-2 minutes and watch while it broils to avoid burning.
Garnish with desired toppings, like sliced jalapeños, diced tomatoes, chopped green onions, and chopped cilantro.
Serve hot with tortilla chips and/or sliced veggies.