Preheat the Oven: Preheat your oven to 180°C (350°F) and line a baking sheet with parchment paper.

Mix Wet Ingredients: In a large bowl, beat the egg with the sugar, vanilla sugar, and a pinch of salt until well combined and slightly frothy.

Add Kefir and Oil: Stir in the kefir and vegetable oil, mixing until smooth.

Combine Dry Ingredients: In a separate bowl, sift together the flour and baking powder. Gradually add the dry mixture to the wet ingredients, stirring until a soft dough forms. The dough should be slightly sticky but manageable.

Shape the Cookies: Scoop tablespoons of dough onto the prepared baking sheet, spacing them about 2 inches apart. Gently flatten the tops with your fingers.

Sprinkle with Cane Sugar: Sprinkle the tops of each cookie with a little cane sugar for added sweetness and crunch.

Bake: Bake in the preheated oven for 12-15 minutes, or until the edges are lightly golden. The cookies should be soft and slightly springy to the touch.

Cool: Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.