Smoothing fondant onto a cake isn't a difficult process but it can become confusing when you have a cake that isn't perfectly round or square. Covering your heart shaped cake with fondant will take a little extra time but even a novice baker can accomplish this task. Remember to tint your fondant before you apply it to the cake and always let the cake cool before you begin icing or decorating with fondant.
Place the pan you used to bake your heart shaped cake on a piece of waxed paper.
Draw a circle around the cake pan onto the waxed paper with a marker, keeping the marker at least 3 inches away from the pan at all times. This will produce a circle much larger than the cake pan.
Remove the cake pan and flip the piece of waxed paper upside down on your work surface. This will prevent any of the marker ink from getting on your fondant.
Flatten ready-to-use fondant onto the waxed paper with a rolling pin until it is 1/8 inch thick. The fondant must completely fill the circle you drew to ensure that it is large enough to cover your heart shaped cake.
Cover the top and sides of your cake with a thin layer of icing. This will help the fondant stick to the cake.
Gently roll the fondant onto the rolling pin so you can move the fondant circle without breaking it.
Unroll the fondant onto the frosted heart shaped cake. Reposition it gently with your hands to centre it on the cake.
Gently smooth the fondant onto the top and sides of the cake. Try to be very gentle to avoid creating finger impressions on the fondant.
Trim away any excess fondant extending past the bottom of the cake with a knife.
If the fondant sticks to your rolling pin, dust it with a small amount of icing sugar. You can purchase tinted fondant or knead in a small amount of paste of gel food colouring until the desired colour is reached.