Sanjaya Maniktala’s Switching Power Supply Design & Optimization is that rare gem.
: Includes Buck efficiency loss teardown diagrams and active reset techniques for Flyback and Forward converters.
The book is designed as a standalone "designer manual" that follows a logical progression: Switching Power Supply Design & Optimization - Google Books
If you buy this book solely for the math, you are missing the point. The unsung hero of the text is the implicit education on PCB parasitics.
Have you read this text? Did you find the section on Voltage Mode vs. Current Mode Control the most helpful, or was it the deep dive into snubber circuits? Let me know in the comments.