HELP..I wanted to make a a larger sized cake (the largest size square pan) for my son's birthday but wanted to make one layer, add filling and put a top layer but the cake was so big I did not know how to get the second layer on top of it without it falling apart. Can anyone help on how to do that please????????

Place the second layer on a cake board the same size or slightly bigger and put in the freezer to firm it up. It will be easier to move around when slightly frozen and on a cake board.

Ok...so once it is firmer I should be able to slide it right off the board onto the first layer correct?

Yes. This is what I do on bigger cakes.

Thank you so much! I kept picturing trying to flip it over onto the first layer and could just see the bottom layer smashing

Partially freeze your cake layers, you can then pick them up and transfer much easier. No breakage or crumbs. But if you use IMBC for icing you must allow the cake to thaw before icing. I have learned that by trial and error, if you ice while frozen the icing will develop deep cracks in the surface as the cake comes to room temperature. So I freeze, dam and fill, then allow to thaw before crumb coating, chilling and final icing.