If you don't have the same size baking tray, simply use one that you have, as long as it's larger: line it, then mark the correct measurements and simply spread the mixture up to the marks.
The roll will remain fresh for up to 4 days, providing it is kept chilled and wrapped firstly in parchment papaer and then in foil.
Macros are for 1 slice and EXCLUDE filling.
The best way to ensure accurate measurement of ingredients is with Metric Kitchen Scales. They are inexpensive and take up very little space. Click
HERE for the ones I use. For U.S. option click
HERE.