STEP 1: Partially freeze your cake layers (on a level surface) before you begin assembling the cake (about an hour before should be sufficient). If the cake is very cold, the buttercream will set quite quickly which will make assembling ALOT easier and your cake won’t end up being the leaning tower of Pisa.
STEP 2: Tint 2/3 of the buttercream a light purple colour and start assembling the cake layers, alternating with buttercream. Check out this video post if you want to see how. Coat the entire cake with a thin layer of frosting then refrigerate to set and finish off with a final layer.
STEP 3: Using a sharp bread knife, cut a cavity out of the cake to create an indent.
STEP 4: Half the remaining buttercream and tint half a deep purple and the other half a dark pink. Cover the cavity with the dark purple buttercream and place a few blobs around the front of the cake. Place blobs of pink frosting in between then using a palette knife smooth the buttercream so the colours blend into each other forming a galaxy/watercolour effect.
STEP 5: Cut the bottom of the swizzle sticks off, then starting from the centre of the indent, stick 3-4 black crystal sticks into the centre of the cake. Stick the purple ones around it. Crush the remaining purple sticks and place the crystals around finishing with a layer of pink and then silver. Dust the centre with black glitter.
STEP 6: Using tweezers, carefully place a line of silverleaf around the edges. If you want, decorate the cake with white chocolate sails dusted with edible silver dust.