Prepare the Meatballs: In a food processor, blend the sun-dried tomatoes, onion, garlic, and basil leaves until finely chopped. In a large bowl, combine this mixture with the ground chicken, egg, Italian herbs, garlic powder, pepper, Parmesan, and breadcrumbs. Mix until just combined, adding more breadcrumbs if the mixture feels too wet.

Form the Meatballs: Shape the mixture into meatballs, each approximately 1 inch in diameter. Set aside.

Sear the Meatballs: Heat 2 tablespoons of reserved sun-dried tomato oil (or olive oil) in a skillet over medium-high heat. Lightly brown the meatballs on all sides, working in batches if needed. This step adds extra flavor but can be skipped for a lighter version.

Assemble in Slow Cooker: Transfer the seared meatballs to the slow cooker. Add the white wine, chicken broth, chopped sun-dried tomatoes, and heavy cream. Stir to combine.

Cook: Cover and cook on low for 4-5 hours or on high for 2-3 hours, until the meatballs are cooked through and tender.

Add Gnocchi and Spinach: Approximately 30 minutes prior to serving, stir the gnocchi and baby spinach into the slow cooker. Stir gently to combine. Let cook until the gnocchi is tender and the spinach has wilted.

Serve and Garnish: Serve the Tuscan meatballs and gnocchi hot, garnished with extra Parmesan if desired.