Prep the pan & cherries. Preheat to 350°F. Generously butter a shallow 9″ pie dish. Arrange cherries evenly on the bottom.
Whisk the batter. In a bowl, whisk together ¾ cup flour, ½ cup sugar, and a pinch of salt. Add 3 large eggs and whisk until smooth. Slowly pour in 1¼ cups milk and 1 tsp vanilla, whisking until silky.
Bake to perfection. Gently pour batter over melted butter and prepared cherries in a pie pan. Bake at 350°F for 40–45 minutes until puffed, lightly golden, and center set.
Cool & serve. Let rest 10 minutes; it will deflate into a rustic soufflé. Dust with powdered sugar before slicing.