It took me a moment to remember how to do it. I kept seeing a few posts on the forum with extra large emojis and I had no idea how they were doing it. But eventually I found with the second set of smile emojis you can "copy image" and then paste a larger version of it. I'm just purposefully scaling it up.
Here's the actual size...
But once it's in image form you can make it extra big like this...