Pre-heat the oven to 350. In a mixing bowl, combine the cream cheese and yogurt and stir together until smooth and well mixed. Spread the cream cheese mixture evenly across the bottom of a 9†pie plate and set aside. Place the ground beef in a large skillet and bring over medium-high heat. Cook the meat, breaking it up into small pieces, until fully browned and cooked through. Add the tomato sauce and chili seasoning and stir together until well combined. Reduce the heat to low and cover for 10 minutes to let the flavors meld. When the chili is done, spread it evenly across the top of the cream cheese layer in the pie plate. Sprinkle the cheddar cheese over top of the chili layer and place the dish in the oven. Bake for 20 minutes until cheese is melted and dish is heated through. Serve warm.