Press fresh raspberries through a fine-mesh sieve to remove seeds and create a smooth puree, ensuring a velvety texture without grittiness in your frosting.

Use softened butter (68-70°F) and cold heavy cream to achieve the perfect emulsion—cold ingredients won't whip properly, while warm ones will result in greasy frosting.

Add raspberry puree after the butter and sugar are fully creamed to prevent the acid from breaking down the mixture, and fold it in gently for optimal color and flavor distribution.

Mix 1-2 tablespoons of cornstarch into your raspberry puree before folding it in to absorb excess moisture and prevent your frosting from becoming too soft or weeping on warm days.

Refrigerate your finished frosting for 15-20 minutes before piping or spreading to achieve cleaner definition and prevent it from sliding off cakes or cupcakes.