1-First, make the raspberry sauce: Combine 12 ounces (340 grams) fresh or frozen raspberries, 3 tablespoons (37 grams) granulated sugar, and 2 tablespoons (30 grams) fresh squeezed lemon juice in a saucepan. Bring it to a boil, then lower the heat and cook until the berries soften. Mash them and press through a fine-mesh strainer to get about 3/4 cup of coulis, then return it to the saucepan and reduce over medium heat until you have 6-7 tablespoons. Let it cool completely that’s your flavorful base.

2-Next, prepare the Swiss meringue: Fill a saucepan with water halfway and bring it to a simmer. In a heatproof bowl over the water (not touching it), whisk 5 large (150 grams) egg whites with 1-1/4 cups (250 grams) granulated sugar constantly until the sugar dissolves and the mixture hits 170°F. This step is crucial for that stable foundation, just like when I first learned and avoided a soupy mess.

3-Then, whip the meringue: Move the bowl to a stand mixer with the whisk attachment and beat on medium-high speed until it’s smooth, glossy, and cool to the touch at 80-85°F. Gradually add 30 tablespoons (424 grams) unsalted butter, one tablespoon at a time, on medium speed the mix might curdle, but keep going until it’s creamy. Finally, fold in 2 tablespoons of the cooled raspberry sauce, adding more a tablespoon at a time for your perfect flavor and color, then frost away.