Preheat oven to 180C/350F/Gas4 Line a low sided baking tray with parchment
This is one of those store cupboard bakes that really is easy to pull together as it is an all-in-one mix. Toss all ingredients for the cake part into your mixer and bring together but don't over mix it or the cake will become tough. Stop once everything is well combined.
Spoon into a lined baking tray and smooth the top. Mine was around 1cm/just under half an inch in depth. Pop into the oven for approximately 20 minutes or until it springs back when gently pressed in the centre.
Leave to cool on wire rack while to mix up the topping. This is a case of add-it-and-mix to get the icing sugar right. Start with your wet ingredients and start stirring in the sifted icing sugar. It takes quite a bit to form a paste so just add and stir until you have the consistency that you like.
When the cake has cooled completely cut into finger shapes. I got this brilliant little cutter that does 3 finger shapes at once. and then split them in half. Spread the gorgeous creamy filling on to the bottom piece and then pop the lid on. Do this with all the little cakes and then dust gently with a little icing sugar. Top each with a mandarin segment and scoff the rest.