This doesn't really count as a tutorial because you should be able to deduce what you need to do, just by looking at it :)
But here is a quick tut anyway...
What you will need:
Some flower pots (I used metal because that is what I had, but I think clay/ceramic pots would look AMAZING)
Cake mix - the recipe I used is here.
Chocolate frosting - I melted about 300g of chocolate and mixed in a few tablespoons of cream, then I let it set (but I left mine a little bit too long)
Pour your cake mixture into the flower pots and bake them according to the recipe.
Then pipe out the frosting.
I originally didn't want to spread the chocolate (as you can see I piped it) BUT because I had left the chocolate to cool for too long it looked a little bit too much like poop:)
So I spread it out and inserted my paper flowers.
I must admit I rushed this a little (I really just wanted to eat the cake:), hence the lack of photos, but if you made an effort with the flower decorations you could use this at a garden party/wedding theme.