Preheat & Prep: Crank up your oven to 400°F (200°C). Generously butter four ramekins, then sprinkle each with sugar, tapping out any excess. Set ramekins on a baking sheet.

Warm the Milk: Pour the milk into a saucepan. Heat gently until it just starts to steam—don’t let it boil!

Make the Egg Base: In a mixing bowl, whisk together the egg yolks, sugar, and cornstarch until smooth and lightened in color.

Temper the Yolks: Slowly whisk the hot milk into the egg yolk mixture. Go slow, whisk constantly, and you’ll avoid scrambled eggs.

Thicken the Custard: Return the mixture to your saucepan and cook over medium heat, stirring nonstop, until it thickens to a pudding-like texture. 

Flavor & Cool: Take the pan off the heat. Stir in the butter and vanilla until melted and smooth. Set aside to cool slightly.

Whip the Egg Whites: In a clean bowl, beat egg whites with cream of tartar (or salt) until soft peaks form. Gradually add 1 tablespoon sugar, continuing to beat until stiff, glossy peaks appear.

Fold & Fill: Gently fold one-third of the whipped whites into the custard base to lighten it up. Carefully fold in the rest, trying not to deflate the mixture. Spoon into prepared ramekins, filling right to the rim. Smooth the tops and run your thumb around the inside edge to help the soufflés rise.

Bake: Slide the ramekins into the hot oven and bake for 12–14 minutes, until puffed and golden. No peeking!

Dust & Serve: Remove from oven, dust with powdered sugar, and serve immediately while gloriously tall and warm.