Heat the oven to 180ºc/160ºc fan and line three 20cm/8inch sandwich cake tins with baking parchment – leave to the side.
In a stand mixer, beat together the butter and light brown sugar for a few minutes until light and fluffy.
Add the flour, eggs and baking powder and beat again
Divide the mixture between the three tins and smooth it over – bake for 25-30 minutes until the cakes are golden and when the cake springs bac
Once baked, leave the cakes to cool in their tins for 10 minutes or so, and then remove and leave to cool fully on a wire rack.
For the Decoration!
Beat the butter with an electric mixer for a couple of minutes to loosen it.
Gradually add the icing sugar on a slow speed until it is combined then speed the mixer up and mix for 3-4 minutes until thoroughly combined and smooth.
Add the cocoa powder to the buttercream and continue mixing. If its really stiff, add in 1tbsp of boiling water at a time until you reach the desired texture.
Keep on beating for 5 minutes until whipped and silky smooth
On the first layer of the cake, pipe your buttercream using a 2d closed star piping tip, and then drizzle/spread some of the caramel on top. Repeat again with the next layer.
For the top layer, pipe on the rest of the buttercream, and add some little swirls. Drizzle over some more caramel. On top of each swirl, add a mini millionaires shortbread bite, or a piece of shortbread.
Sprinkle on some crushed shortbread, some sprinkles, and ENJOY!