Preheat oven to 425° + preheat sheet pan; discard potato plastic + slice as thinly as possible

Spread 1/4-1/2 cup sour cream on crusts + layer potatoes on top (covering the whole pizza); carefully take out sheet pan, place 2 pizzas on pan + bake 7-10 min until crust is crisp + potatoes are tender

Meanwhile, heat skillet over medium; add 2-4 bacon strips + cook, flipping frequently, until browned + cooked through, 4-6 min; let cool slightly + crumble into bite-size pieces

Scatter thinly sliced scallions + crumbled bacon over pizzas; slice + serve