When you whisk the eggs do it softly. It will only take a few minutes and the egg yolk and white won’t be totally combined but they will provide the ‘glue’ which makes them rise and stay together.
video link....http://slowcooker.cooktopcove.com/2016/04/11/old-or-new-bread-works-for-this-tasty-slow-cooker-french-toast-recipe/?src=fbfan_51023&t=fbad&up=20161111&k=lgrhaen017