Wash the potatoes. Boil in a pot of water until tender (about 12-15 minutes).
In a large bowl, combine 1/2 cup of marinara sauce with the remaining ingredients. Incorporate all ingredients together, do not over mix.
Form meat mixture into evenly sized mini loaves. You want a consistent thickness throughout the loaf so that it cooks evenly. Try and to make all loaves a similar size so that they finish cooking at the same time.
Place the mini meatball loaves in the air fryer basket on one side, leaving room for the smashed potatoes on the other. Brush on marinara sauce to the tops of the meatloaves. Air fry at 380 °F for 10 minutes.
Once potatoes are done boiling, carefully remove from boiling water and place on a hard surface, such a baking sheet.
Slightly cut an “x” into each potato with a knife to help it smash easier. Using a bottom of a ramekin, plate, or some other solid kitchen utensil, smash each potato to make it flat.
Add the potatoes to the other half of the air fryer basket. Spray the tops of the potatoes with oil and sprinkle on salt, pepper, and dried rosemary.
Air fry for an additional 5 minutes at 380 °F. Meatloaf should register around 160F when done cooking. Add more time as needed.
Add parmesan cheese to the top of the potatoes. Close the air fryer basket and let the food sit in the warm basket for 1-2 minutes to melt the cheese (do not turn air fryer on unless you desired charred cheese).
Remove contents from air fryer basket, repeat for remaining loaves and potatoes, and enjoy!