How sad.
Maybe you might suggest to her that you’d like to have it sometime. Just once in a while. I bet they make decent frozen or refrigerated ones in the bakery section of the grocery that are single serve. She could pick one kind of dessert pie, and you could have cheesecake. Lots of stores are making smaller servings an option now.
I know that when I realize there’s something my husband appreciates that I don’t often cook or bake, I try to accommodate his wishes if we can manage it, and usually we can.
If she does the shopping most of the time, offer to go instead of her, and surprise her with some single portions, say, cheesecake for you, and her favorite dessert as the another (especially if it’s something you don’t like). She might get the hint. Or maybe even be direct but kind about it.
Lots of ways to get a nibble like that once in a while. ;)
It ain’t gonna happen.................🙄