You can make your recipe book as long as you want. The “30+ page mini recipe book” refers to the number of template designs included; not a limit on how many pages you can create.
You can mix, match, duplicate, and reuse any of the template pages to build a recipe book that fits your needs, whether that’s 10 pages, 50 pages, or even 200 pages.
Canva itself allows you to create recipe books up to around 200 pages, so you’re not limited by the template at all. My templates simply give you a professional starting point; you choose how long your finished book becomes.