Preheat the oven to 350℉. Lightly spray baking sheets with nonstick spray (or line with parchment or silpat mats).
Place the butter in a medium, microwave-safe bowl. Heat in the microwave, just until completely melted. Remove from the microwave and add the brown sugar. Stir until smooth.
In a medium bowl, whisk together the oats, flours, baking soda and salt. Stir into the butter sugar mixture along with dates, egg and vanilla. Fold in the chopped chocolate and mix well.
Drop tablespoonfuls of the cookie dough onto the prepared baking sheets. Bake for about 12 minutes, or until they appear to be set and not gooey in the middles.
Notes
FYI- I *hate* dates, and I loved these cookies. If the dates are chopped finely, you really can't detect them in the cookies at all. You'll sometimes find them in containers in the produce section but they're also available in the dried fruits section and are packaged just like dried cranberries.
There's a good reason for using chopped chocolate over chocolate chips in this recipe. If you use chopped chocolate, the little shards of chocolate get more spread out in the cookies and therefore get more of a chocolate flavor in each cookie. You can certainly sub chocolate chips, but I'd recommend using the mini chocolate chips to get the same spread-out chocolate effect.