Bake 4 x 8" rounds and cut out a piece from one so the other can fit snugly against it

Like this

Buttercream in between the join and across the top

Repeat the shape with the other 2 layers

Place on top of the coated layers, buttercream where they'll join together

Buttercream the top and sides - I chose yellow for my 'cheese pizza' simply adding yellow gel to my remaining plain buttercream. I attempted red like pizza sauce for the sides but I'd already dyed all the buttercream yellow so it came out an orangy pink. Lesson learned lol

Roll out some fondant in grey and cut to a 5 inch diameter circle. This will be for the sewer lid. You need 2 of these, one for the plain base the characters will sit on, the other needs decorating as follows

I used letter stamps and the tip of a butter knife to make the Teenage Murant Ninja Turtle logo and the sewer grate markings. I used offcuts and rolled into balls then flattened to look like screws, using the same knife made the flat head screw markings

For each turtle character roll out 3 fondant balls in green. The head is around 2 inches in diameter, the other 2 are around 1cm but judge by your own eye

Flatten the head slightly and use the butter knife to make the mouth shape. Flatten and pinch the 2 smaller balls and press into the head piece. Use the knife to mark out fingers

For each turtle cut a strip on fondant for the eye mask. The colours needed are red, blue, yellow and purple

Wrap around the head like so

Use more red to cut out 'pepperoni' slices

Place the 'snowman' turtle towards the centre back of the plain grey circle. Build the other 3 around him as shown

Pipe on white icing for eyes and dot with black

Rest the sewer lid against the 'snowman' turtles head when you add the decor to the cake

Add your candles and any other decorations. You could make other 'toppings' if you like - mushrooms would be quite simple in white fondant or pink squares for ham