In your stand mixer with the paddle attachment, beat the butter and confectioners’ sugar on low speed until well combined. Turn the speed to high for 2-3 minutes until light and fluffy.
½ cup unsalted butter, 1 cup confectioners' sugar
Add in the salt, vanilla, and Biscoff spread and beat again on medium speed for 2 minutes.
¼ teaspoon kosher salt, ½ cup Biscoff spread, 1 teaspoon vanilla extract
Add in the heavy cream a tablespoon at a time until it is the consistency you like.
3-5 tablespoons heavy cream
Notes
I make sure that all of my ingredients are at room temperature before I start the recipe, so pull out all of the ingredients before you start baking.Butter: I use European style butter, like Kerry Gold, in my recipes. This will make your frosting much creamier and richer.Salt: If you don’t have kosher salt, halve the amount of salt called for in the recipe. 1 teaspoon kosher salt = ½ teaspoon fine salt.Confectioners' Sugar: I used about 1 cup of confectioners' sugar, but if you feel like your frosting isn't thick enough you can add more, ¼ cup at a time. Amount of Frosting: this recipe makes enough to generously frost an 8x8-inch snack cake, 12 cupcakes or a thin layer of frosting on a 2 layer 8-inch cake. Storage: keep leftover buttercream in an airtight container in the fridge for up to 5 days. Freeze for up to 2 months, let thaw before using and stir.