First up lets make the sponge; preheat the oven to 170°C/150°C/Gas Mark 3. Grease and line a 9” square baking tray, now we’re ready to bake!
First things first, pop the butter in a saucepan with the sugar and syrup and place over a very low heat, stirring occasionally, until melted. Remove from the heat, stir in the milk and set aside to cool for 10 minutes.
In a separate bowl, mix together the flour, Bicarbonate of Soda, ginger and mixed spice. Make a well in the centre and add the egg and gradually pour in the melted mixture, mixing together to make a smooth, thick batter.
Pour the mixture into your prepared baking tray and pop in the oven to bake for 25-30 minutes, until risen and firm to touch. Leave to cool in the tin for 15 minutes, then remove, and pop onto a wire rack to cool completely.
Pop your butter into a large bowl and beat until softened and smooth, it is easiest to do this with an electric hand whisk. Add the icing sugar in a couple of additions and beat together well. Add the Vanilla Extract and caramel and beat again to a lovely smooth buttercream, if it is too firm add a few tsps. of milk to soften. Cover until your sponge is cool.
Once your sponge is cool, cut a circle the same diameter as the top of your jar (cut enough circles for the number of cake jars you are making, these need to be about 1-1½cm thickness). Crumble up the remaining sponge to large crumbs; you can do this either with your hands or a fork. Set aside in a bowl.
Take your jars and pop a few spoonfuls of crumbled sponge in the base of each to create an even sponge base layer, if needed you can use a rolling pin to help compact the sponge. Drizzle some caramel sauce on top of the sponge and then pipe or spoon a layer of buttercream on top. Repeat again adding another layer of crumbled sponge, caramel and buttercream. Finish with a circle of sponge on top (that you previously cut out). – if you are using taller jars you might need to add another layer of crumbled sponge and buttercream before popping on the sponge circle.
Pop the remaining buttercream into a piping bag fitted with an open star nozzle and pipe a buttercream swirl on top of each jar – if you do not have a pipping bag you can add a spoonful of buttercream on top and smooth out using a palette knife or back of a spoon. Drizzle over any remaining caramel sauce and finish with the Reindeer Cheer Sprinkles!