In a small saucepan, bring sugar and 2 tablespoons water to a boil together over medium heat, stirring occasionally. Cook until mixture registers 238° on a candy thermometer.
Meanwhile, in the bowl of a stand mixer fitted with the whisk attachment, beat egg whites at high speed until soft peaks form. With mixer on medium speed, add hot sugar syrup in a slow, steady stream until combined. Increase mixer speed to high, and beat until bowl cools to room temperature, 5 to 6 minutes.
With mixer on medium speed, add butter, a few tablespoons at a time, beating until combined. Add vanilla bean paste, and increase mixer speed to high; beat until well combined. Use immediately.
Recipe by TeaTime Magazine at https://teatimemagazine.com/mini-chocolate-cakes/