Oh those Springerle are persnickety! They even demand their own cookie sheets!
Yep...the cookie sheets you use for baking Springerle will have an impact on the success of you cookies. I have the best results with shiny aluminum pans. Dark colored pans will over-brown and over-bake Springerle. Insulated cookie sheets, while an excellent choice for soft gooey or chewy cookies, also tend to over-brown the bottoms of Springerle cookies.
Now about the size of your cookie sheets.......Make sure you have cookie sheets that have at least 2 inches of space around the sides of the pan in your oven. When I moved and started using a new oven that was wider, but less deep, I did not have much space on the front and back edges of the cookie sheet and experienced some less than good results with cookie sizes that I had never had problems with before. As soon as I replaced the cookie sheets with narrower width cookie sheets, the problems were solved. It is important to remember that much of the success of baking these Springerle cookies is that it is all about controlled leavening. Thus, it makes sense that even circulation in your oven will yield better results!