Preheat the oven to 400°F.  Spray a 9-inch pie plate with cooking spray and set aside.

In a skillet, brown the ground beef over medium heat.  Drain, and return the beef to the skillet.  Add the onion and garlic, and cook for 4-5 minutes.  Remove from the heat.

In a bowl, combine the cream cheese, ranch dressing, chili powder, and ground cumin.  Add the beef mixture and half of the shredded cheese.  Stir to combine.  Transfer the mixture to the prepared pie plate, and sprinkle with the remaining shredded cheese.

Bake for 15-20 minutes until the cheese is golden and bubbly.  Serve with tortilla chips.