Preheat the oven to 180C/160 Fan. Grease and line a 2lb loaf tin, set aside.
Using a mixer, cream together the brown sugar and Stork/Butter until light and fluffy- around 3 minutes.
Gradually add the eggs and flour until well combined- around 20 seconds. Be careful not to overmix.
Put the cake batter into the prepared tin and bake for around 50 minutes - 1 hour 10 minutes until a skewer inserted in the centre comes out clean.
Remove the cake from the oven and leave to cool for 10 minutes. Turn it out onto a wire rack and leave to cool completely, around 1 hour.
To make the buttercream, mix together the soft butter and icing sugar until smooth, around 3-5 minutes. Add the 50g of caramel and mix until just combined.
Pipe the buttercream onto the cake using a Wilton 2D piping tip. Alternatively, spread the buttercream onto the cake using a palette knife or spoon.
To decorate, drizzle extra caramel over the top of the cake using a piping bag or spoon. Sprinkle with fudge chunks or chopped fudge.