First, make the date filling: Remove the pits and skins from the dates. Place the dates in a food processor and pulse twice. Transfer the dates to a skillet, add the butter, and cook over medium heat, stirring until the butter melts. Add the cinnamon and stir until everything is well combined. Remove from heat and set aside to cool.

For the maamoul dough: Combine all the dry ingredients in a bowl and mix well. Add the melted butter and knead, then gradually add the milk. You may not need the full 1/2 cup of milk—add just enough to bring the dough together. Knead until smooth and well combined. Take a piece of dough, flatten it in your hand, place a bit of the date filling in the center, and seal the dough around the filling. Press into a maamoul or cookie mold if you have one. Place the filled cookies on a greased baking sheet. Bake at 350°F (180°C) until the bottoms are golden. Turn on the broiler for a minute or two to brown the tops, then remove from the oven and let cool before serving.