Prepare egg yolk mixture: Separate 3 eggs. Use only 2 egg yolks and 3 egg whites. Slightly beat the 2 egg yolks, then add 15 ml milk and 3 ml vanilla extract. Mix only until the milk is incorporated.
Make the meringue: Hand mix the 3 egg whites for 30 seconds until frothy. Add 1/4 teaspoon cream of tartar. Using an electric mixer, beat the egg whites until bubbly and white. Gradually add 50 g granulated sugar and continue beating until stiff peaks form.
Add cornstarch to meringue: Gradually add 7 g cornstarch to the meringue and fold it through gently.
Prepare dry ingredients: Combine 30 g all-purpose flour with 3 g baking powder and sift to avoid lumps.
Combine yolk mixture and dry ingredients: Add the sifted flour and baking powder to the egg yolk mixture and whisk until thickened but do not overmix.
Fold meringue into yolk batter: Add two scoops of meringue into the yolk batter and whisk until cohesive. Then fold the remaining meringue gently into the batter until just combined, being careful not to overmix.
Prepare pan and molds: Preheat a pan on low heat. Lightly oil the pan. Use a cookie cutter lined with parchment paper as a mold and place it on the pan.
Cook pancakes with steam: Pour the batter into the mold, leaving some headroom for rising. Drizzle a bit of water around the pan and cover with a lid to create steam. Cook for 7 minutes without opening the lid.
Flip and cook other side: Carefully remove the lid and mold. Unwrap the pancake and flip it gently. Add more water to the pan, cover again, and cook for another 7 minutes.
Serve: Remove from pan and serve immediately for best texture and fluffiness.