Ingredients

　　6 tablespoons unsalted butter, room temperature

　　3/4 cup confectioners’ sugar

　　3/4 cup smooth peanut butter, preferably natural

　　3 tablespoons heavy cream

　　In the bowl of an electric mixer fitted with the paddle attachment, combine all ingredients. Beat on medium-high speed until light and fluffy, about 5 minutes, scraping down the sides of the bowl as needed. Use immediately, or transfer to an airtight container and refrigerate up to 3 days. If refrigerated, let filling stand at room temperature to soften before using.

　　Reprinted with permission from Martha Stewart's Baking Handbook by Martha Stewart. © 2005 Clarkson Potter