Heat the oil: Warm olive oil in a large pot over medium-high heat until it shimmers slightly, about 1 minute.
Brown the chicken: Add ground chicken to the pot and cook, breaking it into small crumbles, until no pink remains, about 6 to 7 minutes.
Soften the onion: Stir in diced onion and cook for about 3 minutes, until it turns soft and translucent.
Add the garlic: Add minced garlic and cook for 30 seconds, stirring constantly, until fragrant.
Pour in the broth: Add chicken broth, Italian seasoning, and red pepper flakes if using. Bring the mixture to a gentle boil.
Cook the noodles: Stir in the broken lasagna noodles and simmer for 10 to 12 minutes, stirring occasionally, until the noodles are al dente.
Lower the heat: Reduce the heat to low so the cream and cheese don't scorch on the bottom of the pot.
Melt the cream cheese: Add cubed cream cheese and whisk steadily until it fully melts and the broth looks smooth, about 3 minutes.
Stir in cream and parmesan: Pour in heavy cream and add parmesan cheese, stirring until the soup turns pale and thickens slightly, 2 to 3 minutes.
Wilt the spinach: Add baby spinach and stir just until it wilts into the soup, about 1 minute.
Season and ladle: Taste the soup and adjust salt and black pepper as needed, then ladle into bowls.
