Preheat your oven to 160°C/325°F/Gas Mark 3. Line the baking tray with 12 cases
Beat the sugar and butter with the vanilla essence until light and fluffy.
Add 1 egg, 1 third of the flour and a splash of milk and beat until just combined and repeat until all the ingredients are combined.
Divide the batter between the 12 cases and bake for 20-25 minutes.
Remove and cool in the tins for 10 mins before moving to a wire cooling rack.
For the buttercream:
Pop all the ingredients onto a large bowl and beat on a low speed for about 7 mins until smooth. Add the yellow and green food colouring gradually until you get a lime green colour.
Once the cakes are cooled completely, spread the buttercream on tops of the cakes. Don’t spread it right up to the cases or the buttercream will squash over the sides when you put the fondant rings on.
For the toppers:
Using the white fondant make tiny bone shapes to add to the cauldron later. Make small bats either by hand or with a mould if you have one.
Roll the black fondant out to 3mm thick and cut 12x 68mm circles. Cut the centre out of each circle using the 58mm cutter. Place the rings onto the dome kit to shape them, if you don’t have these you could sit the ring over the end of a coffee mug.
Using the remainder of the black fondant roll ‘sausage-like’ shapes for the rim of the cauldron. Cut to size and with a brush of water, stick to the inside rim of the rings.
Place the rings onto the cakes over the icing so the lime green icing is showing through the middle. Smooth the edge of the black icing along the cake case with your finger to give it a nice rounded edge.
Decorate the top of the lime green buttercream with the eyes, tongues, sprinkles, bats etc. Trim and add the bread stick for the stirrer.