Menenas (Shortbread Filled With Dates and Walnuts)

Ingredients

• ½ cup walnuts
• ¾ cup lightly packed finely chopped pitted dates
• 2 tablespoons hot water
• 2 tablespoons unsalted butter
• ¼ teaspoon ground cinnamon
• ⅛ teaspoon ground cloves
• ½ teaspoon finely grated orange zest
• ½ teaspoon orange blossom water
• 2¼ cups all-purpose flour, plus more for dusting
• ½ cup fine semolina flour
• ½ teaspoon baking powder
• 2 tablespoons confectioners' sugar
• 8 ounces (2 sticks) unsalted butter, cut into small pieces, at room temperature
• 1 tablespoon whole milk
• 1 teaspoon vanilla extract
• 1 cup confectioners’ sugar
• An oval cookie mold, about 2½ by 1¼ inches