In a medium bowl, mix together the butter and cream cheese until well blended. Beat in flour, 1 cup at a time, until the mixture is blended and will form a smooth dough. Refrigerate at least 1 hour.
NOTE: Mixture may be made ahead of time and refrigerated up to 24 hours.
Roll into small balls (approximately 24 one-inch balls) and press into the bottoms and sides of ungreased 1-1/2-inch tart pans or mini-muffin pans to make a shallow shell. Use floured fingers to press dough evenly against bottom and up sides of each muffin cup.
Sprinkle 1/2 cup chopped pecans on top of dough in muffin or tart tins; set aside.
Prepare Egg Filling. Use a spoon to fill each of the dough cups 2/3 full with the Egg Filling mixture. Sprinkle the tops with the remaining 1/2 chopped pecans.
Preheat oven to 325 degrees F.
Bake approximately 20 to 25 minutes or until pastry is golden and filling is puffed.
Remove from oven and let cool slightly in the pan, then remove the cooked Pecan Tassies and let cool completely on a wire cooling rack.
In a bowl, mix together brown sugar, eggs, butter, salt, and vanilla.
Pecan Tassie Cookies Recipe: https://whatscookingamerica.net/Cookie/PecanTassie.htm