Preheat oven to 375°.
Butter a rectangular baking dish or line a pan with parchment.
Whisk flour, baking powder, and salt in a medium bowl.
Separate eggs, placing yolks in the bowl of a stand mixer fitted with the paddle attachment and whites in a separate small bowl.
Add sugar and vanilla to egg yolks and beat on medium-high speed until very pale and fluffy, about 2 minutes.
Reduce speed to medium, add cheese and beat just to combine.
Reduce speed to low. Add milk in 3 additions, incorporating completely after each addition before adding more.
Stream in the melted butter and beat until combined.
Gradually add the dry ingredients and beat until combined, about 1 minute. Scrape batter into a large bowl.
Thoroughly clean and dry mixer bowl to remove any yolk fat.
Combine egg whites and a pinch of salt in bowl.
Using whisk attachment, beat, starting on medium-low speed and gradually increasing to medium-high, until tripled in volume and peaks form, about 2 minutes.
Add half of the egg whites to batter and fold in with a rubber spatula until no streaks remain.
Repeat with remaining egg whites.
Scrape batter into prepared baking dish then sprinkle the sesame seeds over.
Bake, rotating halfway through, until a tester inserted into the center comes out clean, 24–28 minutes.
Let cool slightly before running a spatula or knife along the sides to loosen the sides. Serve.