To brown the butter, place 1/2 cup of cubed butter in a glass pie plate. Cover with a plate to catch any spatters, and microwave for 6-8 minutes. The butter will bubble furiously for a few minutes as all water evaporates out and the milk protein solids begin to brown. Keep an eye, as it can burn quickly. Add more time in 30 second increments if needed. Transfer browned butter to a container (so it doesn’t keep cooking) and allow to come to room temperature.
In a large bowl, beat the butter until it is smooth. Add the cooled brown butter and continue beating for a few minutes. Add the confectioners sugar and beat again until fully combined and smooth again. Add the salt, yolks and vanilla. Mix well. Add the flour and mix just until combined. Add the cranberries and pistachios and stir just until combined.
Turn the dough out onto the counter that has been lightly dusted with confectioners sugar. Roll the dough into a sausage about 2 1/2- 3 inches in diameter. For smaller sizes, roll into a smaller log.
Wrap the log in plastic wrap and refrigerate for at least 2 hours or overnight (you can also freeze it for 30 minutes). Once chilled, unwrap the log and slice it into rounds approx. 1/2 inch thick. Place cookies about 1 inch apart, on a sheet lined with parchment, and bake at 350 for 14 minutes. Allow cookies to rest for 2 minutes before moving to a cooling rack. Enjoy!