1. For crust: place the crackers in a food processor or blender, pulsing until they are fine. Add to a mixing bowl and stir in the melted butter and garlic powder.
2. Press crust mixture into a pie pan or dish and bake at 350 degrees for 5 minutes until it is slightly puffed and browned. Reduce heat to 325.
3. Make the filling next. Beat eggs, then stir in half and half, rosemary, salt, and nutmeg, if desired. Stir in cheeses.
4. Sprinkle thinly sliced apple evenly over baked shell. Pour filling mixture over the apple layer.
5. Bake 40 to 45 minutes or until knife inserted in center comes out clean. Let stand 10 minutes before serving.