For the batter, beat the butter, cream cheese and sugar in mixing bowl until smooth. Add eggs, 1 at a time, beating well after each addition. Stir in vanilla. Add the flour, baking soda, and pudding mix and mix well. For the filling: mix the brown sugar, pistachios and cinnamon in a bowl. To assemble, divide 1/2 of the batter between 2 greased 5 x 9 inch loaf pans. Divide the filling between each pan, spreading evenly. Pour remaining batter over the top of each, spreading evenly. Bake at 325 for 50 to 60 minutes or until golden brown. Makes 2 loaves.