In a mixing bowl, combine the flour, baking soda, baking powder, and salt then mix well.
Cream the butter in a separate mixing bowl and add the sugar (white and brown) while continously mixing until texture becomes fluffy.
Beat-in the eggs on the mixing bowl with butter and sugar then continue mixing until everything is well distributed.
Gradually add the flour-baking soda-baking powder-salt mixture while continously mixing (don't forget to scrape the sides with a silicon spatula).
Put-in the dates and walnuts then mix until well distributed.
Preheat oven to 350 degrees Fahrenheit
Grease the baking pan and pour-in the batter.
Bake for 10 minutes then pull down the temperature to 300 and continue baking for 35 minutes or until done (you may use the toothpick technique)
Remove from the oven and allow to cool down
Slice and wrap individually if desired.
Serve. Share and enjoy!