Begin by beating the egg whites in a glass, metal, or ceramic bowl until they form stiff peaks. This step is essential for achieving the desired lightness and fluffiness in the pancakes.

Lightly grease enough 3 1/2-inch ring molds to fill your frying pan. Place these molds into the pan over a low flame and cover. This setup helps to maintain the structure and rise of the pancakes while cooking.

In a separate bowl, combine the all-purpose flour, sugar, baking powder, and baking soda. Stir to blend the dry ingredients evenly.

In another bowl, whisk together the buttermilk, egg yolks, melted butter, and vanilla extract. Gradually mix this wet mixture into the dry ingredients, stirring until the batter reaches a smooth consistency.

Gently fold the stiff egg whites into the batter, ensuring they are incorporated without overmixing. Small visible bits of egg whites are acceptable, as they will contribute to the fluffiness.

Carefully pour about ½ cup of the batter into each ring mold, then cover the pan. Cook for approximately 5 minutes, or until bubbles begin to form on the surface. Flip the pancakes, still within their molds, and cook for an additional 3 to 4 minutes, until fully set.