DD (Double Deep) 8" & OH (One and Half deep) 6" Round. On a R12" board.
Details:
As sketched. Two tier cake covered in blue as sky. With green on the top under John Deere style tractor. With brown like mud around top of bottom tier. Green covered board. With yellow scroll having green inscription.
Sides of the cake having various, 2 diggers and a dumper truck with some muddy debris around. Including a prominent number (age).