Combine softened butter, confectioners sugar, salt and vanilla in a stand mixer with a paddle attachment or a large bowl if using a hand mixer. Beat on low speed until light and fluffy. It takes about 4~5 minutes for this happen.
¾ cup Unsalted butter, at room temperature, ½ cup Confectioner's sugar, ½ teaspoon Salt, 1 teaspoon Vanilla extract
Add flour, nuts and tutti frutti. Beat until the dough comes together. If the dough seems too dry, then add 1 teaspoon of milk at a time and mix until the dough comes together.
1½ cups All purpose flour, ¾ cup Chopped Nuts (pistachios, almonds, cashews & walnuts), ¾ cup Tutti frutti*, 1~2 tablespoons Milk, optional
Divide the dough in half and shape into a log. Roll the log in plastic wrap. Refrigerate the log for at least 1 hour.*
Preheat the oven to 300°F. Lightly grease 2 baking pans or line them with parchment paper.
Remove the cookie logs from the freezer and set them aside for a few minutes to soften a little bit. Use a sharp knife and slice the log into ¼" thick pieces.
Place the cookies 1" apart on the prepared baking sheet. Bake for 25~35 minutes or until they feel firm to touch and the bottoms are lightly browned. They will not brown much, baking longer at a lower temperature prevent them from darkening.
Remove the cookies from the oven and place them a cooling rack to cool completely. Store them in an airtight container.