Gingersnap Pie Crust - how to sub butter as binder I made a delicious pumpkin pie for Thanksgiving using Trader Joe's triple-ginger gingersnaps. The ginger flavor really complements the pumpkin. Following a basic recipe, I added a fair amount of butter to the ground gingersnaps. Although it was delicious, I'd like to find a way to do this without it being so rich and calorie-laden. So my question is: 

Does anyone have experience making a gingersnap pie crust using something other than butter or other fat to bind the crumbs, given that there is already fat in the gingersnaps --  perhaps egg? egg white? water? (Perhaps similar experience with a graham cracker crust could apply.)
I have seen some recipes that use milk instead of butter. They would be slightly healthier, but I find that the crust burns easier and feels drier and more brittle. Keep in mind that a lot of the calories come from the ginger snaps that themselves contain sugar and butter. I haven't done the math, but I think the calories from the butter are negligible compared to the calories in the pie filling and the gingersnaps.

For a healthier crust, I would use a base of some unsweetened cracker and mix in the same spices that are in gingersnap cookies when I mix the crumbs with butter. That would cut some calories, while retaining the feel of a butter crust.