Step 1

Beat butter, white sugar, and brown sugar with an electric mixer in a large bowl until smooth. Add eggs, one at a time, allowing each egg to blend into the butter mixture before adding the next. Beat in vanilla extract. Combine all-purpose flour, whole wheat flour, baking soda, salt, and cinnamon in a separate bowl; stir into butter mixture. Fold in oats and dates. Cover and chill dough for at least one hour.

Step 2

Preheat oven to 375 degrees F (190 degrees C). Grease two baking sheets.

Step 3

Roll dough into walnut-sized balls and place 2 inches apart onto baking sheets. Flatten each cookie with a large fork.

Step 4

Bake in preheated oven until cookies are golden brown, 8 to 10 minutes. Allow cookies to cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely.