Thanks for your help - it turns out her mom misunderstood and it IS a DUTCH apple pie, not a french apple pie, that they want. I mentioned the icing and raisins and she looked so disgusted, it was hilarious. Thank god I asked. LOL!
I should have clarified, I was going to make a ‘test pie’ for their engagement party which I am hosting as well, not surprise them with a pie at their wedding without them having tasted it! Once I know if it’s their style or not, I will make it (or adapt it) for the big day!