Can I make this pastry in advance?

[Dilbertian]

@leafinthewind I only ever use your pastry for hamantaschen - it's perfect! Can I make the pastry beforehand? Leave it in the fridge or on the counter for, say, 24h before I make and bake the hamantaschen?

In case leafinthewind isn't around, the ingredients are egg, sugar, vegetable oil, plain flour, salt and
baking powder.

I'm leaning towards it being fine to make in advance, because baking powder is heat-activated, but what about the egg?

It'll be fine for a day or 2 in the fridge

I think it'll be fine in the fridge too, using the same logic you used. Never actually tried it, though, I confess.