uhmmmm, you’re making a recipe that is going to end up with a fixed amount of volume.
the alternative is to just keep making more stuff until the pan is full? unlikely approach…
so you have the same number of cups / cubic inches / etc but using the two pans that volume will spread out over more area and the resulting cake will be thinner.
9x13 = 117 sq inches; 9x9=81 sq inches, times 2 pans = 162 sq inches
thinner will bake quicker than thicker.
