I found a recipe for cookies without eggs, so this could be also a vegan recipe.
Vegans don't use eggs and milk so the milk down could be replaced with soya milk. Most magarines are made from soybean oil or a blend of oils, beu actually contain trace amounds of dairy products such as whey or lactose too. So check first.
The recipe is:
100 gr margarine
130 gr white sugar
1 tsp vanilla
1 tsp baking powder
2 spoons of milk
300 gr all propose flour
a pinch of salt
I made also one with eggs, so I take some photos
It should be tender, I put them for half an hour in fridge. Bake them for 8-10 minutes at the temperature of 180°C in the pre-heated baking oven.