In a medium pan over medium-high add onion and I Can’t Believe It’s Not Butter, cook, stirring occasionally, until tender.
Add spinach; cover and cook until it’s wilted, about 2 minutes.
Remove pan from stove; stir in marinara sauce and chicken.
Use the calzone dough recipe/2 ingredient dough; knead and roll on a floured surface
Divide dough into 4 pieces. Use a cookie cutter if needed.
Place a quarter of the spinach mixture and a quarter of mozzarella cheese on one half.
Fold dough over filling to form half-moons, pinching edges to seal.
Coat calzones well with ICBINB.
Place calzones in the air fryer basket or on the pan, and cook at 325°F until dough is golden brown for 8 minutes, then flip and cook for another 4 minutes.