To help ensure a clean and cohesive design throughout your cookbook, font sizes are preset within each template and are not adjustable on recipe pages, covers, or section title pages.
While it is not possible to change the size of the font on the page, it IS possible to change the font style while you're building your book. To change your font, go to the 'Templates' tab in your book-building dashboard and scroll down to the fonts section. Any font that's labelled with a gold star with require a Premium Membership. A Premium Membership does not have to be purchased ahead of time; it can be purchased at the same time as you're purchasing your finished book.
If you’re hoping to personalize the design further — especially on covers, title pages, tables of contents, or section title pages — the “Create & Upload Your Own Design” template is a great option and gives you full control over the layout.