Preheat your oven to 375°F.
Brown the ground beef in a skillet over medium-high heat until very crispy. Drain the excess fat.
In a large mixing bowl, combine the softened cream cheese, sour cream, and mashed potatoes until completely smooth.
Fold in the diced fresh jalapeños, crispy beef bits, half of the cheddar cheese, half of the Monterey Jack cheese, green onions, and garlic powder.
Spread the mixture evenly into a 9x9 inch baking dish.
Top with the remaining cheddar and Monterey Jack cheeses.
Bake for 20-25 minutes until the edges are bubbly and the cheese is golden brown.
Garnish with extra green onions and serve hot with tortilla chips or celery sticks.