Preheat oven to 350 degrees and spray a 9x13 baking dish with cooking spray.
Peel, quarter, and boil potatoes in a large pot for 15-20 minutes or until potatoes are fork tender.
Add the cream cheese, sour cream, milk, and garlic salt. Beat with a mixture until creamy.
Fold in half of the bacon, cheese, and jalapenos.
Spoon mixture into the baking dish and top with the remaining cheddar and bacon. Cover with foil and bake for 30 minutes. Uncover and sprinkle remaining 1 cup of jalapenos on top. Bake for an additional 5-10 minutes or until cheese is melted and jalapenos are crispy.