• Preheat oven to 350 degrees F. In a large bowl sift together all-purpose flour; sugar, unsweetened cocoa powder; cinnamon; cloves; nutmeg; baking powder and a pinch of salt.
• Add cubed butter (at room temperature) and use your fingers, a pastry cutter or even your electric mixer, if you prefer, to cut the butter into the flour.
• Stir in finely chopped walnuts and orange zest.
• Make a well in the center of the mixture and add a beaten egg, stir into the flour. Stir in the milk and shape into a dough. Add extra milk, if necessary, to ensure that the dough holds together. The dough will be quite firm and slightly sticky. At this point, I prefer using my hands to gather the dough together and shape it into a ball.
• Scoop pieces of dough using a cookie scoop for even sizing (I used a 1 tbsp sized scoop) and roll into a ball. Place on a baking sheet coated with cooking spray or parchment paper if it is not a non stick pan. They do not have to be placed too far apart as they don't spread much during baking.
• Bake for 18-20 minutes. Transfer to a wire rack to cool while you prepare the glaze.

To glaze

• In a medium sized bowl whisk powdered sugar and milk until you have a glaze of desired consistency. I prefer my glaze on the thin side. Dip the tops of each cookie in the glaze allowing the excess to drip off. Transfer to the wire rack to set. Alternately, you may use a pastry brush to apply the glaze. 
• Once the glaze has hardened, store the cookies in an airtight container separating layers of cookies with wax or parchment paper to prevent them from sticking.