Easy tray bake (with icing)

This is a very easy tray-bake/birthday cake/bake sale type of cake.  I made two this morning for my son's birthday party tomorrow, but they are so easy you could easily rustle one up as a pud or a snack.

To make the cake, I preheated the oven to 160ºC and greased/lined a 20x20cm baking tin.  Then I mixed together (I used kitchenaid with paddle) 110g self-raising flour, 110g caster sugar, 110g softened unsalted butter, 1 tsp baking powder, 2 large eggs and 1 tsp vanilla extract (don;t smash it on the kitchen floor like I did...).  Whizz it all together and spoon into the pan.  Try to level it out as best you can and get it into the corners properly.  Bake for 16 minutes then turn out, top side down onto a wire rack to cool.  This gives you a nice flat surface for your icing to go on.

To ice it I mixed 200g icing sugar with 55ml of boiling water then added a pinprick of gel colouring.  I find it best to dollop it all into the middle of the cooled cake and gently spread it out with the back of a spoon to the edges.  Whilst the icing is soft, scatter your favourite sprinkles/edible glitter and leave to 'set'.  I cut it into 9 squares, but you can go bigger or smaller according to your needs.  To fancy it up, sometimes I put a square in a cake case to make it look more presentable but you can, of course, sneak a slice and eat it from your hand!  

To adapt mine into birthday party cake I coloured my icing pale blue (although it looks white on the photos), sprinkled sugar strands and edible glitter over it and later added a ribbon to hide the sides and stuck in a few candy coloured candles.  Easy to make, easy to cut up and easy to eat makes it a good option for those manic toddler parties....