You can use a knife, but I use the Wilton saw thing. It's really not that difficult to handle, just be gentle, and it it cracks it doesn't really matter because the icing will cover all of your sins!
Well, My in depth answer to your question is....."I DON'T"...LOL
I usually layer them, because I have a real problem trying to torte them!
Some on the site just use a cake board to slide under the cake when torting, and it works fine for them.....but boy do I make a mess when I try to do it!
well the next bigger size for sheet cakes is the full sheet (two half sheets place long sides together) You would torte them and fill them seperately.
Here's how I do it. place both cakes on your board or whatever support you are using, some people use the cake cutter but in this case it's not wide enough. with a long serrated knife cut each side through the middle [------------------] this way. To keep your cut straight, don't attempt to cut all the way through on your first pass, let the knife do the work. just keep going round and round till you get through. It gets crooked when you try to hard. Now hopefully you used parchment paper when you baked the cake. don't take that off yet, but do remove the top part of your torted cake (mark the front of the board with either a little cut in it or a small mark.) that way you will know which way is front and back. lay your top piece down. fill the cake with whatever you are goint to fill it with don't forget to put some "glue" in the middle or you will have a nasty canyon on your cake. Now place the top back on that side and do the other side just the same way. finish basefrosting it and decorate away. Just to warn you in advance, a full sheet covered in bc will be very very heavy and if it's filled even heavier. So you want to make sure that you have it on a sturdy enough board or support so that it won't buckle when you pick it up.
Hope this helped ya a little.
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