This was a par-boiled idea, but I was making espresso the other day and realized the grounds are quite fine, so of course I thought of flocking. I have a birthday for a guy coming up and he loves coffee (it's not as easy for me to make cards for guys for some reason). I thought of making a coffee cake and covering my cake with grounds, then topping it with real whole coffee beans.
I tried using double sided tape, but the grounds (unused) wouldn't stay on. The glue holds an amazingly thick layer of grounds when I did a test. So I put down light blue vinyl on the cake where I didn't want coffee. Unfortunately the glue stayed on the vinyl too. So I had to apply the glue carefully before dousing with grounds. It's a good thing I used brown paper so any bare patches blend in.
Now that it's done, it makes me think of a chocolate mocha cake – plus it's like scratch and sniff sticker, except no scratching is needed!