If you ask me what my most frequently referenced dessert cookbook is, I'd tell you it's The Joy of Cooking: All About Pies and Tarts. This little book by Irma Rombauer, Marion Rombauer Becker and Ethan Becker shines with great American pie recipes and tips on foolproof pie dough, how to make hand pies, and finessing the fine art of latticework.
It's a keeper and I think that can largely be attributed to the fact that it's a concentrated tome that's devoted to one small subject and is researched within an inch of its life--not as common with cookbooks these days. From what I've gathered, it's now out of print, but there are many used copies out there; I snagged one at Green Apple Books so it's certainly not impossible.
What I love about the book is it's such a good starting point. All of the recipes in Joy of Cooking: All About Pies and Tarts are solid, from their Shoofly Pie to the Vanilla Cream Pie or Sweet Potato Pie. I always find myself starting here, exploring at least one other recipe and then making adaptations to come up with my own version. So why go to all this work in the first place? For many food bloggers who like to cite recipes on their webpage, adapting an original recipe is important for copyright and legal reasons. Many folks have written on this subject in thought-provoking and sometimes even contentious ways, including Diane Jacob and David Lebovitz.