I ended up making a plum tart with a pine nut "frangipane" filling. I used a short, sweet crust as base. I ground some pine nuts with powder sugar, added some flour and an egg for the filling, marinated the plums with cognac and sugar, baked everything in 375 for about 40 minutes.
I used the left over juices from the marinate and reduced it to a glazed and glaze the top of the finished tart.
It's delicious. A good strong cognac and plum flavor, tart and sweet at the same time.