Do you want them to be floppy or have some shape? If you want them to have shape you might want to try knitting the inside and outside separately and stitching them together. You can trim plastic canvas to shape and stitch it inside the ears. This should hold up okay if you decide to machine wash the hat later. You can get sheets of plastic canvas at any craft store. Walmart should carry it, too. Here’s what it looks like if you don’t know.
If I understand what you want correctly, you could knit them in the round in 2 colors, and duplicate stitch/embroider/crochet an ear border if you like. Think a very large thumb on a mitten…
I recently made a bunny myself and used the free [link"]](http://www.knittinghelp.com/forum/[URL=http://knittingfromtheheart.blogspot.com/)[Honey Bunny](http://knittingfromtheheart.blogspot.com/) pattern. I made the ears stockinette so they’d curl slightly like a lop eared bunny’s ears do. Had to make it wider and longer than the pattern called for to make it work. Made the arms and legs longer than the pattern called for too to give it less of a teddy bear feel. Turned out super cute