Adjust cooking rack to the bottom placement and preheat toaster oven to 400°F on the BAKE setting.
Place pita on the baking sheet and spread with preserves. Top with feta, half the pecans, and spinach. Arrange apple slices in a single layer on top of the spinach. Sprinkle with remaining pecans and cheddar cheese.
Bake until the pita edges are browned and the cheese is melted and bubbly, about 8 to 11 minutes.
Remove pan from toaster oven, top with fresh rosemary (if using) and allow pizza to cool for 3 minutes before slicing and devouring!