Cook bacon in two batches in a large soup pot or Dutch oven over medium-high heat until crisp. Remove bacon from pot onto a paper towel-lined plate, then drain all but about a Tbsp of bacon grease from the pot.
Saute onion and garlic in the reserved bacon grease over medium heat for about five minutes, stirring occasionally, or until onions are browned and begin to soften.
While the potatoes are simmering, crumble your cooked bacon. Once potatoes are tender, mash them right into the soup with a potato masher until the soup is at your desired consistency (see Notes), then add the crushed red pepper and pepper and stir in spinach until wilted.
Stir in the garlic & herb cheese, as well as half of the bacon. Continue to simmer and stir until the cheese is completely incorporated, then serve your potato soup topped with reserved crumbled bacon + green onions (optional).
I don't bother to peel Yukon Gold potatoes for soup because the skin is so thin you don't notice it in there -- so why lose the nutrients? Instead of using a potato masher, you can also blend the soup with an immersion blender if you prefer your potato soup less chunky or wilt in the spinach and then blend everything together if you want a green & creamy soup. I find that mashing with the potato masher, however, is enough to give a great potato flavor and texture to the broth -- while still leaving chunks of potato in there for a heartier soup.