Pre-heat oven to 350 degrees. Lightly grease baking sheets or line with parchment paper or Silpats.
Place butter in a microwave-safe bowl and place in microwave to melt. Remove from microwave and add brown sugar, stir until just smooth.
In the bowl of an electric mixer or in a large bowl with a hand mixer, whisk together oats, flours, baking soda and salt.
Mix in butter and sugar mixture, along with egg, vanilla, and dates. Fold in chocolate chips.
Using a tablespoon, gently drop cookie dough onto your prepared baking sheets. Bake for about 12-15 minutes, or until the cookies set.