The size of the intro pages can be increased. Click on the box for the advanced editor and you will be given control over the page. Highlight all of the text and click on the font size option.
Please note, the size shown in the font size option is not what will appear on the page, it will be smaller. For size 12 text in your cookbook you need about a size 22 in the advanced editor tool. Please sure to save and then preview your page to make sure it is what you want.