Dutch Apple Pie with Sour Cream Custard

When my daughter took the first slice of this pie, she asked me what the white stuff was...  knowing that if I said sour cream anything, she'd turn her nose up in a huff, I quickly snipped "vanilla ice cream".  She didn't bat an eye, and proceeded to tell me this was the best pie I have ever made as she licked her bowl clean.  High praise from a  7 year old whose favorite past time is telling me I'm wrong.  Now, if an adult asked me the same question, I'd probably say something like "it's a custard and it's delicious".  Then I'd say, "imagine a cheese danish with slightly sweetened cinnamon scented apples....."  Honestly, I've never made a pie like this before- and I have nothing to compare it to- but I loved it and I hope you will too  If you like source material, I used Hoosier Mama and Silver Palate as starting points, and my intuition and pantry (what's available) from there.  Pie is endlessly adaptable, so improvise as you see fit!