How to Make It
In a large bowl, beat the butter until creamy. Beat in the confectioners’ sugar, almonds and coconut. Beat in 1 of the eggs. Add the 2 3/4 cups of flour, the allspice, salt and nutmeg and beat just until combined. Divide the dough in half and flatten into disks, then wrap in plastic and refrigerate until firm, at least 2 hours.
Liberally flour a large sheet of wax paper. Transfer 1 of the disks of dough to the paper, dust with flour and cover with another sheet of wax paper. Roll out the dough to a 12-inch square about 1/4 inch thick, lifting and repositioning the paper from time to time. Set the dough on a cookie sheet and refrigerate until firm, at least 30 minutes. Repeat with the second disk of dough.
Preheat the oven to 350°. Line 3 large baking sheets with parchment paper. Remove the top sheet of wax paper from 1 square of rolled-out dough and set it on a cutting board. Cut the dough into 1 1/2-inch-wide strips. Using a ruler positioned on the diagonal, cut 1 1/2-inch-wide strips, to create diamonds. Using a thin spatula, arrange the cookies 3/4 inch apart on the baking sheets. Repeat with the second square of dough. Gather all of the scraps into a disk and refrigerate until firm. Roll out the dough 1/4 inch thick, then cut more diamonds.
In a small bowl, beat the remaining egg with the milk, vanilla and espresso. Brush the diamonds with the glaze. Bake the cookies on the middle and lower racks of the oven for about 17 minutes, or until browned, shifting the pans from top to bottom and back to front halfway through. Let the cookies cool on the baking sheet.