✓ Preheat oven to 375°F (190°C). Grease four small ramekins with unsalted butter and dust them lightly with granulated sugar.

✓ In a bowl, whisk the egg yolks with lemon juice and zest until well combined.

✓ Sift together 1/4 cup granulated sugar, salt, and cream of tartar into another bowl.

✓ In a separate clean bowl, beat egg whites until they hold soft peaks. Gradually add the dry ingredients while continuously beating to stiff peaks.

✓ Gently fold the yolk mixture into the beaten egg whites until just combined. Overmixing can make soufflés dense and fall, so be gentle here.

✓ Divide the batter evenly among the prepared ramekins. The batter should be smooth and consistent; any lumps will result in an uneven texture.

✓ Place the ramekins on a baking sheet to catch any overflow. Bake for 15 minutes or until the soufflés rise, turn golden brown, and are set. Ensure they’ve fully risen before checking.

✓ Remove from oven and dust with powdered sugar if desired. Serve immediately while still puffy and light; cooling will cause them to deflate slightly.