Combine all of the ingredients (except for the pecan halves if using) in a medium sized bowl and mix well.Using 2 spoons or a medium cookie scoop, scoop the dough into 12 mounds and place on parchment or wax paper on a small platter or cookie sheet.Garnish each cookie with a pecan half if desired.Chill until firm and serve.Store in an airtight container in the refrigerator for up to one week or in the freezer for up to 3 months.