Firstly, Preheat the oven to 375 degrees. Spray a 9x13 baker with non-stick spray and set aside.
Peel 5 pounds of russet potatoes. Slice thinly with a knife, mandolin, or make short work with a food processor.
Place potatoes in a pot with water. Salt. Allow coming to a boil.
While potatoes are boiling, shred your cheese.
Once potatoes come to a boil, lower heat to a simmer, and allow to cook 5 minutes, or until just tender.
In a large microwave bowl, microwave your cream cheese so it softens and begins to melt. This should take 1 to 1 1/2 minutes.
Once the cream cheese is very soft, stir in the milk, cream, garlic & onion powders.
Pour a tiny bit of this cream sauce into the bottom of your baking dish.
Drain your potato slices.
Add 1/2 of the potato slices to your baking dish. Pour over 1/2 of your cream sauce, sprinkle 1/2 of your cheeses, bacon, and jalapenos on this layer (the rest is for the top!).
Repeat the previous step. Basically, you made 2 layers.
Cook for 30 minutes in your preheated oven. Your dish should be golden on top, and the sauce should be bubbly. In conclusion, Allow to sit and rest for 5 minutes and garnish with sour cream, sliced green onions, and paprika.