1-Ensure all tools and bowls are clean, dry, and grease-free; wipe with lemon juice or white vinegar if needed.

2-Separate eggs carefully, adding one egg white at a time to the mixing bowl to avoid yolk contamination.

3-Whisk the sugar into the egg whites, then place the bowl over a saucepan with two inches of simmering water, making sure the bowl does not touch the water. Constantly whisk until the sugar dissolves and the mixture is frothy and thin, reaching 160°F (71°C).

4-Transfer the mixture to a stand mixer’s bowl and beat with the whisk attachment on medium-high speed until stiff, glossy peaks form and it is no longer warm to the touch, about 10-15 minutes (longer in humid conditions). If stiff peaks are not reached, refrigerate uncovered for 10 minutes and continue beating.

5-Wait for the mixture and bowl to cool to room temperature (around 70°F/21°C) before adding the butter.

6-Switch to the paddle attachment, then add the butter one tablespoon at a time on medium-high speed, waiting for each piece to incorporate fully before adding the next.

7-Add the vanilla extract and salt, then beat on medium speed for about 30 seconds until creamy and smooth.

8-If the frosting curdles or becomes soupy: For curdled frosting, gently warm over simmering water until the edges melt (1-2 minutes), then beat until smooth; for soupy frosting, refrigerate for 20 minutes and re-whip, repeating as necessary.