X is for Xanthan Gum
Now this post is almost a 180-turn from the last post...this post is about using non-wheat flour. When baking with a gluten-free flour (such as rice, buckwheat, or chickpea), a fine powdery substance called xanthan gum is often added to the recipe to help with the texture of whatever baked good is being made. This is a handy tip to know in the event you ever have to bake for someone with celiac disease. Who knows, you might make that person's whole day by knowing about this powdery stuff.
So just in case you ever need a gluten-free recipe, here's a pretty extensive list of recipes that use xanthan gum, including blueberry muffins, chocolate chip cookies, and pumpkin bread... because no one should EVER miss out on pumpkin bread.
As for recipes starting with X, the closest thing I got was this recipe for X-traordinary Rich Chocolate Pudding Recipe. Also Hot Cross Buns look pretty delicious and they have X's on them... ok maybe they're supposed to be crosses, but turn 'em diagonal and it's an X! Right??
And my totally random recipe that I just feel like posting because it looks good is this one for Blueberry Buttermilk Coffee Cake. I LOVE breakfast desserts. :)