Ingredients:

  • 8 oz (225 g) High-Quality White Chocolate, chopped finely
  • 5 Large Egg Whites (about 150 ml), room temperature
  • 1 cup (200 g) Granulated Sugar (Caster Sugar preferred)
  • 1/4 tsp (1.25 ml) Fine Sea Salt
  • 1 cup (2 sticks / 227 g) Unsalted Butter, cubed, slightly cool
  • 1 tsp (5 ml) Pure Vanilla Extract

Instructions:

  1. Melt the White Chocolate: Place the chopped white chocolate in a small, heatproof bowl set over a simmering pan of water (bain-marie). Stir constantly until fully melted and silky smooth. Remove the bowl and set the melted chocolate aside to cool completely to barely warm/room temperature before proceeding.
  2. Set up the Bain-Marie: Fill a medium saucepan with about 2 inches of water and bring it to a simmer. Ensure the mixing bowl does not touch the water.
  3. Combine Ingredients: Add the egg whites, sugar, and salt to the heatproof mixing bowl. Whisk constantly by hand over the simmering water.
  4. Heat and Dissolve: Continue whisking until the mixture reaches 160°F (71°C) on the thermometer. When a small amount rubbed between your fingers feels perfectly smooth, the sugar is dissolved.
  5. Whip the Meringue: Immediately transfer the bowl to the stand mixer fitted with the whisk attachment. Start whipping on medium-low speed for 1 minute, then increase to medium-high.
  6. Whip to Stiff Peaks: Whip until the meringue holds stiff, glossy peaks and the outside of the bowl is completely cool to the the touch (this takes 8–12 minutes). The meringue must be cool before adding butter.
  7. Switch Attachments: Replace the whisk attachment with the paddle attachment. Turn the mixer to low speed.
  8. Add Butter Gradually: Add the cool, cubed butter one piece at a time, waiting about 5–10 seconds between additions. The mixture will look curdled or soupy, which is normal. Do not stop mixing.
  9. Whip to Emulsion: Increase the speed to medium and continue beating for 3–5 minutes until the mixture transforms into a smooth, thick, and fluffy buttercream that holds its shape.
  10. Add Flavouring: Scrape down the bowl. Add the vanilla extract and mix briefly on low speed.
  11. Incorporate White Chocolate: With the mixer on low, slowly drizzle the completely cooled white chocolate into the buttercream.
  12. Final Beat: Beat on medium speed for 1 minute until the white chocolate is fully incorporated, achieving a homogenous and silky finish.