Canterbury Naturals makes an apple cake mix that is the closest to an apple cake served at the local croissant bakery/cafe.  http://www.labou.com

My eighty-seven year old neighbor and I have tried every apple cake recipe we can get our hot little hands on, trying to duplicate the flavor, to no avail.  The apples are layered throughout the cake and it is rather dark, not dark dark, in color.  At first I thought it might contain molasses but there is no hint of molasses flavoring.  If anyone has any suggestion or recipe, I would be so grateful.  She is in fragile health, fighting cancer, but still determined to keep going, so much so, she made it to the Denny’s breakfast giveaway yesterday at the crack of dawn! She still loves to bake and would very much enjoy being able to make a similar cake from scratch.

VB:
  Good afternoon to you. The only thing that I can suggest to you is, is that I believe those apples are prepared in “BOILED CIDER”.
Many bakers do that type of cooking to prepare the sliced apples prior being placed in the pie pastry…this way the apples do not shrink inside the pie dough when baking leaving a large void in the pie. Cooking the apples in boiled cider is a early American technique. It will leave a amber color to the apples.
  I hope my info will help you & your friend. If you require more info on on this ingredient I will be here in the morning.
Give my best to your friend & enjoy the rest of the day.

  ~FRESHKID.

VB, In addition to the suggestion from Freshkid, I would try using brown sugar rather than white.  This just gives some brown colour to the crumb.  I do hope you reproduce the cake - and have fun trying!
Annie

Have you taken a look at the list of ingredients on the mix? That might give you some clues, too.