Cook the mixture until softened and then transfer to the slow cooker. Add the potatoes, stock, onion powder, garlic powder, salt and pepper to the slow cooker.
5 Cover and cook on high for 4 hours or low for 6-7 hours.
6 Using a ladle, pour 2 cups of the potato/broth mixture to a blender. CAREFULLY, puree the mixture until smooth. (Cover the top of the blender with a towel, hot liquids in a blender can explode and the towel will protect you.)
7 Pour the pureed potato mixture back into the slow cooker and stir to combine, Add the half and half, yogurt and cheese. Stir to combine.
8 Serve topped with the reserved bacon, cheese and scallions.