Showing Product Options as check boxes

My client (a granola company) would like to offer a customized granola to his customers, I know this is possible through product options, but I am unsure how to show the options as a checkbox menu instead of dropdown.

For example,

The Product: Custom Granola

The Options: Cranberries, Apples, Walnuts, Cinnamon, et cetera,

Each would be an extra 50 cents added to the price of the whole bag.

I could work around the Drop Downs, but I'd rather have a checkbox for these options, as they could have all or none added to their granola.

Thanks in advance

I'm not finding the drop down declaration in that file, and I being dumb or missing something?

You rule.

Thanks.