Comment by Loughla
And yet, if you make it like I do, there always manages to be one piece that is ice cold while the rest is shockingly hot. Even if you're start with warm ingredients.
Physics does not apply to lasagna.
Also I suck at making lasagna.
I don't know how you cook your lasagna, but cooking for longer at a lower temperature usually results in more even heating than cooking for less long at a higher temperature. (This is one of the reasons microwaves are so terrible at heating evenly.) If you're not already, that may help.
(I also imagine using the circulation in a convection oven might help as well. Also, preheating your oven! Even if it's a toaster oven.)