AI'm planning to make a couple of cakes for my husband's birthday. One of which is a simple rectangular cake with an edible image. I want to use a pound cake recipe for this cake. I was told by the cake supply store that the biggest image that can be made is 7.5 by 10 inches. What size of pan do I need to use for this cake? Also, is it reasonable for me to double the recipe and create a two layer cake with a lemon custard filling? I'm wondering if a pound cake is too dense for a two layer cake. Also, will one basic pound cake recipe (using a bundt pan) be big enough to make a rectangular cakebigg enough for the picture size?

7.5 x 10 is almost the same square inches (75 sq") as a 9" square (81 sq"), which takes half of a recipe for a two layer cake, but you can probably use a 9x13 cake pan and one box of mix/recipe and have plenty.

You should be able to layer the pound cake and fill it, but make sure your custard filling is firmly thick, so the top layer doesn't slide off. Shouldn't be any trouble with just two layers. 

AThanks for the reply? Are you saying that one 9X13 cake cut into two layers should suffice?

That should be fine.  Use a Wilton Cake Lifter, or a flat cookie sheet to lift the top layer off after you tort it, and it shouldn't break. After you do your filling and frosting, put the image on in the center, smooth it on, let it sit a minute, then pipe on a nice border to hide the edges.
 

AI did a 13x9 cake a few weeks ago, and I used a flexible cutting board to lift the top layer off. It was the kind that come color coded in a four pack made from thin plastic. It worked great.