I would say you bake your sheet cakes, cut into strips the width you need for the size sponge bob you are making, and then stack them like a barrel cake. So, two layers, dowel, then stack two more layers, dowel, and so on until you get your height, then run 2 or 3 long dowels all the way through, evenly spaced across. I would think that would work. Hope that makes sense, it would be easier to draw you a picture but I can't
hi, i did a standing up spongebob a few years ago (see the link below)
i made a cake sheet, cut it into rectangles about 7"x3" and stacked them on top of each other. i had two thick dowels that went through the cake and were screwed into a board. i then used an apple corer in each layer to make the holes as the support dowels were quite big.