VEGAN - I haven’t tried it yet, but you could sub the butter for coconut oil and the eggs for a chia or flax egg - though I’d make it as 4 flax/chia eggs. Let me know if you do try!
COCONUT SUGAR - if you can’t find coconut sugar, then rapadura, demerera , raw cane or muscovado sugar, though the last 3 are more refined.
If possible, try using organic grass-fed butter and eggs.