Preheat oven to 350°F (175°C).

In a large mixing bowl, combine flour, oatmeal, cocoa, sugar, butter, eggs, vanilla, and walnut extract (if using).

Mix all ingredients until well combined.

If the mixture is too dry, add a small amount of milk to help combine the ingredients.

Taste the batter and adjust the amount of sugar to your preference.

Place spoonfuls of batter onto a lightly greased cookie sheet.

Bake for 8-12 minutes, depending on the size of the cookies and desired level of chewiness.

For chewier cookies, bake for a shorter time.

For crispier cookies, bake for a longer time.

Let cool slightly before serving.