My sister in law made the cake above for her daughter's second birthday based on a picture she found online here from a retail shop.
There are so many good tutorials on fondant on the web. These are the basic steps she took but if this is your first time working with fondant, do yourself a favor and read up on trouble shooting before you begin.
First bake all of your cakes, let them cool and ice them. They need to be slightly cool or completely room temperature to apply the fondant. Casie used pans similar to these. I will note here that she used craft store's 40% off coupons for all the supplies. She used box cake mix but made the frosting. The frosting is for helping the fondant stick to the cake and also nice for people who don't like the fondant and peel it off.
Casie purchased Wilton brand fondant, work with it in as small of sections as possible keeping the rest covered and sealed. Knead the fondant till soft and pliable. Start rolling your first piece out on a little powdered sugar until it is about a 1/8th to 1/4 inch thick and will cover the top and sides of your cake. This is hard work and will be time consuming :)
Using your roller lay the piece of fondant over the cake. Cut off excess. Smooth sides and tops with your hands till you have one smooth surface. Use a little cornstarch or heat and pressure from your hands to smooth cracks. If you have too many cracks you either let it dry out too much or you didn't knead it enough. We had tons of cracks but this is a great first time fondant cake because you can use those hearts to cover the mistakes!
Once you cover all three cakes roll out the red fondant and cut hearts of three different sizes out - this part is easy and fun. Casie used icing color to die the small amount she used for the hearts but it took the whole container and several hours for it to turn a true red. You can also buy red fondant. You need to let the red sit for several hours or a day wrapped up after you color it so it won't bleed onto the white.
To get the cakes crooked looking she used wooden cake dowels. Two went flush into the cake and two stuck out about 2 inches or so.
Put round cardboard cake circles under each cake - and just stack them on the dowels - really it is that easy. Wrap red ribbon around the bottom of each layer.
Finally put the hearts on randomly to cover imperfections.
Then put your tissue paper between the layers to hide the dowels.
Think of all the fun variations to the hearts - letters, numbers, animals, people - anything you can get a cookie cutter for! I am thinking there are some adorable Dr. Seuss themes that would be perfect for crooked cake. If you want something different than tissue paper - paint or decorate your dowels before stacking the cake.
More on Elliana's birthday here.