Ingredients
FOR THE CAKE
  • cups / 225g cake flour all purpose flour
  • tsp baking powder
  • 4 eggs
  • 225 g / 16 tablespoons margarine softened ( 2 sticks / 8 oz)
  • 1 cup / 225g caster sugar superfine sugar ( 7 oz)
  • 1 teaspoon vanilla essence / extract
  • 2 tsp / 10 ml milk
FOR THE BUTTERCREAM FROSTING
  • 225 g / 16 tablespoons margarine softened ( 2 sticks / 8 oz)
  • 375 g / 3 cups icing /powdered sugar sift if there are any lumps
  • 1 1/2 to 2 tablespoons of milk
  • 1 teaspoons vanilla extract
  • Rolled fondant colored to your preference SEE NOTE 1
Instructions
FOR THE CAKE
  1. Preheat the oven to 160ºC / 320 °F
  2. Grease and line a 20cm square baking tin
  3. Sift the flour and baking powder into a large bowl.
  4. Add the eggs, margarine,caster sugar, vanilla extract and milk and beat until thoroughly mixed.
  5. Pour into the tin
  6. Bake for 25-30 minutes. To check if the cake is cooked insert a skewer and if it comes out clean the cake is ready.
  7. Leave to cool in the tin for about 10 minutes and then move to a wire rack to cool completely. Place in the fridge before cutting through the cake to divide into 2 equal layers. Then using a square cookie cutter as a guide cut into 12 equal sized squares. I used a 6cm square cookie cutter.
  8. Spread a layer of jam and buttercream on 6 of the cut squares and sandwich with the remaining 6.
  9. Using a palette knife, apply the buttercream on the sandwiched cakes. Making sure that the corners are neat and smooth all around. Place in the fridge for about 20 minutes and then add another layer of buttercream making sure that it is smooth and neat. Place in the fridge for 20 minutes again to allow the buttercream to firm up making it easier when you are covering with the fondant

  10. Knead the fondant and roll out on a clean dry surface lightly dusted with powdered sugar or corn flour. Cover the individual cakes and using a cake smoother to shape and push out any bumps around the top and the edges. Cut out excess fondant at the base of the cake to use as decorating as you prefer.

FOR THE BUTTERCREAM
  1. Beat the margarine in a mixer until it is creamy. Scrape your bowl. Add milk and extract and blend slowly until combined. Raise speed to medium and beat to form a smooth butter mixture.
  2. Add half of the powdered sugar and blend on low until combined. Srape bowl, add the remaining sugar and set the mixer to medium low and blend for 2-3 minutes.
  3. Resist the urge to add more milk right away because the buttercream will thin out as it mixes.
  4. After mixing on low for 2-3 minutes you can choose to add more milk, 1 teaspoon at a time, to reach your desired consistency.
  5. Frosting can be made softer with the addition of milk, 1/2 teaspoon at a time. This will keep for 3 days at room temperature or 2 weeks refrigerated
Recipe Notes

NOTE 1 

I usually just buy white fondant and then colour it with gel or powdered colouring. Try not use the liquid food colouring because it will make the fondant too sticky and a bit more difficult to work with.