Super Fluffy Gluten-Free Japanese Souffle Pancakes

Combine flour, buttermilk, vanilla, baking powder, egg yolks, and salt for batter in a bowl.

Whip egg whites for meringue in a glass, metal, or ceramic bowl on medium-high speed until foamy. With the mixer running, gradually add sugar and cream of tartar. Continue to whip until soft to medium peaks form. When the beater is pulled from the whites, the peaks will curve back down a little instead of sticking straight up. The whipped whites will turn opaque and significantly increase in volume.

Mix 1/3 of the whipped whites into the pancake batter. Use a spatula or wooden spoon to fold in remaining whites, in several additions, being sure there are no large clumps of egg whites in the batter.

Grease the inside of round metal molds and place molds into a lightly greased pan over medium-low heat. Fill molds 2/3 high with batter. Cover the pan and cook until bottoms are golden brown and bubbles break the surface, about 10 minutes. Flip, cover, and cook until golden brown on the other side and tops spring back when touched, about 5 more minutes.