Diet Whole Wheat Castella

Sift the whole wheat flour and baking powder together.

Separate the eggs into whites and yolks.

Add a pinch of salt to the egg whites and whip until stiff peaks form.

Mix the yolks with oligosaccharide syrup and vanilla extract.

Add the sifted whole wheat flour to the yolk mixture and blend gently.

Fold the whipped egg whites into the batter in three additions.

Pour the batter into a pan lined with parchment paper.

Bake in a preheated oven at 170°C (338°F) for 30 minutes.

Cool and cut into easy-to-eat pieces.