Season chicken evenly on both sides with 3/4 teaspoon salt, 3/4 teaspoon black pepper, and 1/4 teaspoon paprika.
Heat olive oil in an extra-large skillet over medium-high heat. Working in batches, add chicken and cook until browned on both sides, 4 to 5 minutes, flipping halfway through. Transfer chicken to a plate.
Combine chicken broth, sun-dried tomatoes, garlic, Italian seasoning, remaining 1/4 teaspoon salt, 1/4 teaspoon pepper, 1/4 teaspoon paprika and crushed red pepper in a 6-quart slow cooker. Mix until well combined. Place seared chicken into the slow cooker.
Cover and cook on Low for 4 to 4 1/2 hours or on High for 2 1/2 to 3 hours, until chicken is tender and a thermometer inserted into the thickest portion registers 165 degrees F (74 degrees C).
Transfer chicken to a plate; cover with foil. If cooking on Low heat setting, increase heat to High. Stir spinach, cream cheese, whipping cream, and 1/2 cup Parmesan cheese into the slow cooker. Cover and cook on High until cream cheese is melted and spinach is wilted, 15 minutes.
Stir until smooth. Return chicken to the slow cooker and cook until heated through, about 10 minutes more.
Sprinkle remaining 1/2 cup Parmesan cheese over chicken before serving. Recipe developed by Jaelyn Luong
