French Buttercream

Combine sugar and water: In a small saucepan, combine the sugar and water.

Cook the sugar: Without stirring, bring the sugar mixture to a gentle boil and use a candy thermometer to monitor the temperature. The sugar needs to reach 240°F (115°C). This should take no longer than 6 minutes.

Whip the egg yolks: While the sugar comes to temperature, get to work on the egg yolks. Add egg yolks and salt to the bowl of a stand mixer fitted with the whisk attachment. Whisk the yolks over medium speed until they are a very pale yellow color and fluffy, about 5 minutes.

Decrease the mixer's speed to low and slowly stream sugar mixture into whipped egg yolks: Once the sugar has reached 240°F (115°C),

Continue to whisk the egg yolks and sugar mixture: After all of the sugar has been added, increase the mixer's speed to high and continue whipping the egg and sugar mixture until the outside of the bowl is just at room temperature. An excellent way to test this is to place the underside of your forearm against the bottom of the bowl. If it's no longer warm, you can begin adding the butter.

Add the butter: Decrease the mixer's speed to medium-low, then begin adding the softened butter, Allow each portion of butter to fully incorporate into the egg-sugar mixture before adding the next piece. The buttercream will go from very voluminous to deflated midway through adding butter. The volume will be restored once all of the butter has been added. This step should take no longer than 6 minutes.

Add the vanilla extract: After the butter has been added, scrape down the bowl and add the vanilla extract. Turn the mixer back up to medium-high speed and whip the buttercream for 3 additional minutes. The buttercream should be an ivory color and will appear airy and fluffy.

Store the buttercream: Use the buttercream as desired immediately or store for 3 to 4 days in a covered container in the refrigerator.