I am baking a 12"x3" deep cake for a baby shower. I need to cut it down to 6 blocks and feed approx 25 people. What would anyone recommend for size blocks. Do I need to bake another smaller cake also? Thanks for any advice.

Would 4" square blocks be sufficient?

Omg --you're hurting my head.
You're making 6 blocks?
You want 4" cubes to serve 25?
You're baking a 12" cake one inch too short (of the 4") or one inch too short (to layer it up and make two 2"layers).

So ok --I got it if I understand what you mean and I might not--but I'm charging extra for this

I mean you gotta torte this into 2 one inch tall sections. Then cut it into thirds each way so you have nine sections of cake that have three torted pieces in each stack.

You will have 27 squares that are 4x4x1 by baking off a 12" sguare three inches tall.

So you get 8 servings from each 4" cube

So you need 4 cubes to get 25 servings so if each cube has 4 layers and 4x4=16 you will have enough cake because you will have 9 leftover from the original 27 4x4x1 inch squares.

But you can get 6 total 4" cubes out of it if you want. But your cake has to bake three inches tall all over to get that much out of it. Y'know how it's sometimes a little lower in the corners.

Why not bake 2 two inch cakes??