Prepare cold butter and liquid ingredients. Dice the butter and keep it refrigerated.
Mix together the sweetener, salt, and dry ingredients.
Cut in the butter until it reaches a rice-like texture.
Add eggs, yogurt, vanilla oil, and milk, and mix until just combined into a dough.
Split the dough in half, stack, and repeat 4-5 times.
Shape the dough into a rectangle, wrap in plastic, and refrigerate for 1 hour.
Cut into bite-sized pieces and space them apart on a baking pan.
Brush with egg wash and sprinkle sugar on top. If the dough softens, refrigerate again.
Bake at 180°C for 15-18 minutes.