Preheat oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment.

Reserve 2 tablespoons green onions for garnish and add remaining green onions to a medium bowl. Add ¼ cup Parmesan cheese and crushed crackers. Pour ¼ cup half-and-half over the crumbs and add egg and garlic. Add ground chicken and sprinkle with salt and pepper. Mix until combined and stir in mozzarella cheese. Wet hands with water and roll meat mixture into 24 meatballs. Place meatballs on prepared baking sheet.

Bake in the preheated oven for 10 minutes (meatballs may not be cooked all the way through at this point).

Meanwhile, add bacon to a deep skillet or saucepan and place over medium-high heat. Cook, stirring occasionally until bacon is crisp. Pour in alfredo sauce and add remaining half and half to the sauce jar. Shake the jar to release any remaining sauce and pour into the pan. Bring to a simmer, reduce heat, and simmer 3 minutes.

Add meatballs to the sauce and return to a simmer. Cook 5 minutes. Add remaining Parmesan cheese, lemon zest, lemon juice, and crushed red pepper.

Reduce heat to low and stir in sour cream. Stir in water to loosen the sauce a bit and adjust seasoning if necessary. Do not allow mixture to boil. Remove from heat and serve meatballs with sauce over pasta if desired. Garnish with reserved green onions and more crushed red pepper if desired.