In a large bow, combine ground turkey, egg, Italian bread crumbs, Parmesan cheese, garlic, powder, parsley, salt, and pepper. Stir until well-distributed but do not overmix.
Shape turkey mixture into 1-inch diameter small meatballs and set aside.
PRESS the SAUTE mode button on the Instant Pot. When HOT appears on the display, add 1 tablespoon of olive oil.
Place a layer of the meatballs in the Instant Pot and cook for about 3 minutes, turning as needed to brown all sides. Cook the meatballs in 2 to 3 batches, adding more olive oil as needed.
Carefully remove the meatballs from the pot and set aside.
Add the remaining 1 tablespoon of oil olive. Add the onions, celery, and carrots. Cook, stirring occasionally, for about 2 to 4 minutes or until softened.
Add the meatballs, Italian seasoning, and salt and pepper to taste on top of the vegetables.
Add the chicken broth. Do NOT stir.
Turn off the SAUTE setting. Close and lock the lid, and set the floating valve in the SEALING. Cook on HIGH pressure for 5 minutes.
Once finished, do a QUICK RELEASE. Carefully remove the lid.
Press the SAUTE MODE again and add the acini de pepe. Cook for about 6 to 8 minutes or until al dente.
Press the CANCEL button to turn off the SAUTE mode. Add the baby spinach and push down into the broth.
Ladle into serving bowls and garnish with shredded Parmesan cheese. Serve hot.