Preheat the oven to 400°F (200°C). Arrange the oven racks in the upper and lower thirds of the oven. Line two baking sheets with parchment paper to prevent sticking.

In a medium mixing bowl, whisk together the flour, baking soda, salt, cinnamon, nutmeg, allspice, and cloves until well blended. Set aside.

In a large mixing bowl, beat the butter and brown sugar using a hand mixer on medium speed (or a stand mixer fitted with the paddle attachment) until light and fluffy, approximately 4–5 minutes.

Add the egg and vanilla extract to the butter mixture, beating until the mixture becomes smooth and creamy, about 1 minute.

Reduce the mixer speed to low and pour in the milk, mixing just until incorporated. The batter should have a soft and slightly creamy consistency.

Gradually add the prepared dry mixture to the wet ingredients, folding gently with a rubber spatula until no visible streaks of flour remain. Avoid overmixing to maintain a tender cookie texture.

Add the chopped dates and toasted walnuts to the dough and fold until evenly distributed. The dough will be thick and slightly sticky.

Using a medium cookie scoop or a spoon, portion about 2 tablespoons of dough per cookie. Place each portion onto the prepared baking sheets, leaving about 3 inches of space between each cookie to allow for spreading.

Bake both trays simultaneously for 10–12 minutes, rotating and swapping the pans halfway through the baking time. The cookies should puff slightly, the edges should turn golden brown, and the centers should appear set.

Remove the cookies from the oven and allow them to rest on the baking sheets for 5 minutes before transferring to a wire rack to cool completely. Once cooled, store in an airtight container for up to 5 days.