Американский крем для выравнивания торта (швейцарская меренга на белках)

Ingredients for my Swiss Meringue Recipe, demonstrated in this video* -4oz egg whites (use fresh and not packaged pasteurized egg whites) -8oz granulated sugar -12oz softened butter (unsalted!) -a pinch of salt -1-2 Tbsp vanilla extract (or other flavoring; in this video I used about 1 tbsp)