In a large bowl, whisk together the rolled oats, whole wheat flour, chopped nuts, raisins, baking soda, ground cinnamon, and salt.

In another bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy, about 3-5 minutes.

Beat in the egg and then stir in the vanilla extract.

Gradually add the dry ingredients to the wet mixture until just combined.

Stir in the milk until the dough is slightly sticky but holds its shape.

Optionally, chill the dough in the refrigerator for at least 30 minutes.

Preheat the oven to 375°F (190°C) and line a baking sheet with parchment paper.

Drop rounded tablespoons of dough onto the baking sheet, leaving 2 inches between cookies.

Optionally, flatten the dough balls for thinner cookies.

Bake for 10-12 minutes or until the edges are golden brown.

Allow the cookies to cool on the baking sheet before transferring to a wire rack.