Blend the flour, ground almond, baking powder, baking soda, salt and vanilla sugar together in a bowl. In another bowl, whisk together yogurt, milk, and egg yolk. Blend into the flour mixture just until all ingredients are moistened.
- Beat egg white until stiff. Fold into the batter until well incorporated. Melt a small amount of butter in a pan or skillet on the medium heat. Add 3 tablespoons batter into the skillet, tilt skillet to spread slightly. When bubbles are popping about 2 to 3 minutes, turn over and cook the other side until browned, about 2 minutes longer.