We currently build our emails in a different editor outside SFMC and then create them via HTML Paste. We now need to add a dynamic content block for the hero image going forward. I attempted to add the div for adding a content block, and the block is showing up when we create the email via paste, however, we aren't able to see any content to drag into it. I have the sinking feeling that we're going to have to create a template with the email code and then create an email with that template just to be able to add that block.
Please tell me if there is a better way than creating that email, basically, twice. Our emails are not currently in a format that easily lends itself to going pure Content Builder creation and are not likely to be so any time soon.