Preheat oven to 425 C.
Prepare pizza dough according to package directions, or make your own
Place the sliced potatoes, 1 tsp garlic powder, cayenne pepper, onion powder, salt and pepper in a skillet with about 2cups water, just enough to cover the potatoes. Cook covered on medium-high heat until potatoes are tender. Remove lid and simmer until most of the water is gone (alternatively you can drain remaining water if your potatoes are tender enough).
Add oil to the skillet and pan-fry the potatoes until lightly golden brown, about 5 minutes.
Mix 1 tsp garlic powder with ½ cup sour cream, and use this as your pizza sauce base.
Layer the potatoes on the pizza crust to cover it entirely; it’s OK if they overlap.
Next, top the potatoes with bacon, then the shredded cheese.
Place pizza in the oven and cook according to your pizza dough instructions.
Remove from oven and top with the fresh green onion and sour cream as garnish or as a side for dipping.