Whisk together flour and vanilla sugar in a medium size mixing bowl.
Add beer and vegetable oil to the mixture, knead until a soft dough texture is attained.
Using a pastry bench scraper divide the dough into 10 pieces, each weighing approximately 120-125 g.
With the palm of your hand, flatten the first ball and then use a rolling pin to roll out the dough to approximately 20 cm (8″) diameter.
Using a pizza cutter or a sharp knife cut the stretched dough round into 8 equal sections.
Put a teaspoon full of jam at the bottom, at the flat side of each cut triangle.
Take each corner of the triangle’s bottom, pull the dough over the jam and press ends together, sealing the joint and creating a closed pocket with jam.
Roll the dough towards the top of the triangle, creating a cylinder. Curve the cylinder ends gently into a crescent shape and place on a parchment paper lined baking sheet, seam down.
Repeat the same with other 9 dough balls.
Bake at 200 C (392 F) in pre-warmed oven, rack in the middle, for 15-20 minutes or until the crescent edges start to appear a light golden brown. Don’t let cookies brown completely, they should remain light coloured.
Add approximately two cups of confectioners sugar into a medium size mixing bowl. Roll hot crescent cookies in the sugar right after taken from the oven while they are still hot. The cookies should be coated generously since there is no sugar in the dough!
Cool the cookies on a wire rack. Store in a sealed container at room temperature.