In a large bowl, beat the cream cheese until smooth. Stir in the sour cream, chopped jalapeños, lime juice, taco seasoning, garlic powder, and a pinch of salt until well combined.
Spread the mixture evenly into an 8-inch square baking dish or similar size dish like the rectangle dish shown.
Top with shredded cheese, tomatoes, and onions. If serving immediately, go ahead and layer the lettuce on top. If serving later or in batches, keep the lettuce on the side to add fresh as needed.
Serve with tortilla chips and your favorite taco sauce or hot sauce on the side.