In a large skillet over medium heat, cook the ground beef and sausage until browned, breaking it apart with a spoon. Drain excess fat if necessary.
Reduce heat to low and add the softened cream cheese, refried beans, diced tomatoes, taco seasoning, garlic powder, onion powder, salt, and pepper. Stir until well combined and the cream cheese is melted.
Stir in half of the cheddar and Monterey Jack cheeses, mixing until melted and creamy.
Transfer the mixture to a baking dish and spread evenly. Top with the remaining cheddar and Monterey Jack cheeses.
Bake in a preheated oven at 350°F for 20-25 minutes, or until the cheese is bubbly and golden.
Remove from the oven and let it cool for a few minutes. Garnish with sliced green onions before serving.
Serve warm with tortilla chips for dipping.