Baking a bomb cake

By Elkse Joubert on July 24, 2012 in Johané Neilson

Baking party cakes for kids is very rewarding.

I love the creativity involved and the sheer delight on the birthday girl or boy’s faces when confronted with so much frosting! Older kids are more difficult to please, though. When our Copy Editor Lucinda asked me to bake a cake for her 10-year-old daughter Kia’s spy party, I have to admit I was a little out of my depth. Give me a princess cake any day, but a spy theme? Not having seen or made a spy cake before, it took some conceptualising, but here’s what I came up with. It hit me – kaboom! – I’d bake a bomb.

First, bake the cakes. This Hot milk sponge cake recipe is enough for 1 cake baked in a 23cm, ovenproof glass mixing bowl. You will have to double the recipe in order to make the two halves of the Bomb. I made one cake plain white and added 25ml red food colouring to the second batch so the assembled cake will have white and red layers, but more on that later. Your cakes should look like this when done.

Hot milk sponge cake
• 4 eggs
• 250g castor sugar
• 5ml vanilla
• 280g cake flour
• 15ml baking powder
• 250ml milk
• 100g butter

1 Grease a 23cm ovenproof glass mixing bowl, sieve over some flour, shake to cover the surface and discard the excess.
2 Beat the eggs, sugar and vanilla together until light and fluffy. Sift the flour and baking powder together. Melt the butter and milk together.
3 Now add the flour mixture and the milk mixture alternately to the beaten eggs, folding after each addition until well combined. Bake in a preheated oven at 180°C for approximately 45 minutes or until an inserted skewer comes out clean. Turn out onto a wire rack and allow the cake to cool completely.

For the dynamite!
You need
• Red prepared ‘plastic’ icing (If you can’t find packaged red, make your own by adding red powder food colouring to white prepared icing and kneading through until the colour is right.)
• Marshmallows
• Melted chocolate
• Thin strips of red and yellow ‘liquorice’ (optional)

Roll out the red prepared icing to an even thickness of 5mm. Cut 5 rectangles as long as 4 marshmallows and wide enough to wrap around completely. Spread chocolate on the rectangles, top with the marshmallows and roll up to resemble dynamite. Allow to rest so the chocolate can harden. We also added thin strips of red and yellow ‘liquorice’ to make up the fuses.

For the decoration
You need
• 1kg black prepared ‘plastic’ icing (for decorations and to cover the cake)
• White prepared ‘plastic’ icing and yellow food colouring powder
• 1 long piece of liquorice
• Optional: 1 egg white, 250ml icing sugar and red food colouring.

*I found pre-prepared black ‘plastic’ icing at a baking shop. I highly recommend buying this colour pre-prepared as it is a nightmare to make at home; to get a deep black colour, you end up using so much food colouring that the icing tastes metallic.

1 Use the prepared icing to make: a 3cm-wide, 1cm-thick circle and make a hole for your liquorice fuse. Colour a small ball of icing yellow and cut a large star-shaped background with spiky edges and some stars. Cut the birthday child’s name in white, ensuring that the background is big enough for the name to fit on it.
2 For the timer you need a 4cm black circle and a 3cm white circle. Mix the egg white and icing sugar together with a drop of red food colouring. Spoon into a piping bag and use to pipe the dials on the watch face. Alternatively, scour sweet shops for a candy version.

For the frosting
• 250g butter
• 250ml icing sugar
• 250g dark chocolate, melted
• 25ml milk

Beat together the butter and sugar until fluffy. Add the melted chocolate and milk and continue beating until combined.

To assemble the cake:

1 Use a bread knife to slice each cake into two layers; it helps to be at eye level with the knife. Put a small dollop of frosting on the cake board where you are going to position the cake and place the smaller layer of the white cake onto the board, topdown. Spread thickly with frosting and top with the larger red layer. Do the same with the other two layers to form the bomb shape, alternating white cake, frosting, red cake, frosting…
2 Smooth frosting around the whole cake, minsert a wooden skewer in the middle of the cake and cut off the protruding skewer. This will keep the cake sturdy and prevent it from slipping and sliding while icing.

3 Roll out the black preprepared icing, using a combination of cornflour and icing sugar to keep it from sticking to the work surface. Lift the icing and cover the bomb. Use your hands to smooth the icing over the round cake and tuck it in underneath. Don’t worry too much about cracks just yet; I have the perfect trick for that!
4 Cut off the excess icing around the base of the cake.
5 Dust off any excess icing sugar/cornflour mixture with a dry brush. Now use clean water to brush over the whole cake.

6 Use clean water to stick the name of the birthday girl or boy onto the yellow background with spiky edges, and then to the cake. Use a toothpick to secure the liquorice fuse.
7 Add the dynamite to the side of the cake and use the stars to ‘hide’any flaws on the back of the cake.
8 Add the birthday girl or boy’s age in black and dust with edible gold dust. And you are ready to party!