Hi
@baldbaker, welcome to the site.
It's fabulous that you want to make a tractor cake, and you can do so using any of the following options.
The easiest option is to find a tractor tin and use that (although this could be expensive). However, It would give you the required shape, and you would only have to decorate it.
The next option would be to make a 2D version of the cake, as in bake a rectangular cake (I would use Madeira or something similar), draw a tractor template on paper, cut out the shape of the tractor and the wheels, and then cover the cake in icing/fondant or pipe it.
The third option is to make a rectangular Madeira or Pound cake, carve the basic shapes of the tractor in 3D, stack it, coat it, and decorate it with icing or fondant. You could then make the wheels out of Rice Krispies and chocolate and cover them with icing or fondant.
I made this cake for my daughter some years ago but it gives you an idea of how a carved cake would look and then decorated in icing/fondant.
This is the racing car I recently made for my daughter's birthday.
The cake is made from Madeira so that it was easier to carve into shape. I then covered the cake in Renshaws poppy red, black, grey, yellow and lincoln green icing. I pre-dyed the flesh colour for the face using paprika sugarflair dye, and the scarf is made using white icing that was dyed using Wilton's ivory coloured dye. The pig and pug on the cake were pre-made by my daughter, and she requested they be put onto the...
Another option would be to make a normal cake and then make a tractor topper in either 2D or 3D, depending on your skill set. You can see below I made a train topper so you could do something similar and make a tractor topper if the idea of cutting/carving and decorating a cake is a little too much.
View attachment 10157
I hope this helps.
Best wishes
Angie