Pat chicken dry; season with salt, pepper, paprika, and Italian seasoning on both sides.
Crisp the bacon in a large skillet over medium heat; transfer to a plate.
Add olive oil to drippings; sear chicken until browned, 4–5 minutes per side.
Move chicken to a plate; reduce heat to medium-low.
Melt butter in the skillet; sauté garlic until fragrant, about 30 seconds.
Pour in chicken broth; scrape browned bits and simmer for 2 minutes.
Stir in cream, Parmesan, red pepper flakes, and lemon juice; simmer until slightly thickened.
For thicker sauce, whisk cornstarch with water; stir into sauce and simmer one minute.
Fold in spinach; cook until wilted.
Return chicken and bacon to the pan; simmer until chicken is cooked through.
Rest 2 minutes; garnish with parsley and serve.