In large resealable plastic zip lock bag, combine 1 cup of the marinade and the tenderloin; seal bag. Marinate in refrigerator for 30 minutes or more. Remove meat from bag and discard marinade. Grill meat, using indirect heat method, until no longer pink, about 35 minutes, turning once and basting with the 1/4 c of marinade. Let stand 10 minutes, before slicing. In a medium saucepan, combine the 2 Tablespoons of marinade and apple pie filling. Cook over low heat until heated throughout. Spoon over meat slices.
Peach pie filling works good too. as does cherry. I have since made it with chunky applesauce with brown sugar and cinnamon; delicious!