For jam, bring apple, sugar, vinegar and lemon (juice & zest) to a boil. Add vanilla, turn heat to low and cover. Reduce by ½, about 25 min. Let cool for 1 hour.
In medium saucepan, heat EVOO. Season salmon w/ salt & pepper. Cook about 3 min per side until desired doneness. Transfer to an oven-safe dish & cover.
Melt butter in same pan used for salmon. Add shallots, saute for about 5 min. Add sugar & vinegar, cook until sugar is dissolved. Transfer to a blender, add honey and truffle oil, puree until smooth.