Funny story, I had made this recipe once and absolutely loved it! So I made it again, but as I was making the crust I couldnt figure out why the texture was different. It was only after I baked it I realized....I forgot the butter!! I thought I was screwed, I ruined the whole thing like an idiot. (how does one forget butter in a crust right?) So I tried it, and to my surprise it was still really good. So for any butter nazis out there, leave out the butter, and just add 1 Tb more oil to the crust :) just make it a day ahead to allow the crust to soften a bit (the day of its too chewy).
Anyway, even through the mistake it's great and I adjusted a few things to make it even better imo! Instead of orange segments, I added 1 c extra cranberries, and an extra 1/4 c sugar to the filling. I also make 1 1/2 recipe worth of crust, while using only white flour, and a mix of walnuts and oats. To omit the egg, use 1 Tb ground flax meal + 3 Tb hot water, stir and let set til the consistency of a beaten egg. If your trying to add an extra half batch of crust like I suggested, use 1 1/2 Tb flax to 4/1/2 Tb water.