Preheat oven to 325 degrees F. For filling: In a large bowl, stir together hazelnuts, 1/3 cup of the sugar, and the 1/4 cup cocoa powder. Set aside.

Brush the bottom of a 13x9x2-inch baking pan with some of the melted butter. Unroll phyllo dough; cover with plastic wrap. (As you work, keep the phyllo covered to prevent it from drying out, removing sheets as you need them.) Layer one-fourth (5 or 6) of the phyllo sheets in the prepared baking pan, brushing each sheet generously with some of the melted butter. Sprinkle with about 1-1/4 cups of the filling. Repeat layering phyllo sheets and filling two more times, brushing each sheet with more butter.

Layer the remaining phyllo sheets on top of filling, brushing each sheet with more butter. Drizzle with any remaining butter. Using a sharp knife, cut into 24 to 48 diamond-, rectangle-, or square-shape pieces.

Bake in the preheated oven for 35 to 45 minutes or until golden brown. Cool slightly in pan on a wire rack.

Meanwhile, for syrup: In a medium saucepan, stir together the remaining 1 cup sugar, the water, hazelnut syrup, orange peel, and orange juice. Bring to boiling; reduce heat. Simmer, uncovered, about 15 minutes or until reduced to 1 cup. Pour the syrup evenly over slightly cooled baklava in the pan. Cool completely. Before serving, sprinkle with additional cocoa powder. Makes 24 to 48 cookies.

Layer cookies between waxed paper in an airtight container; cover. Store in the refrigerator for up to 3 days or freeze for up to 3 months. To serve, thaw cookies at room temperature for 1 hour if frozen.

To toast hazelnuts (filberts), preheat oven to 350 degrees F . Spread nuts in a single layer in a shallow baking pan. Bake in preheated oven about 10 minutes or until toasted, stirring once. Place the warm nuts on a clean kitchen towel. Rub the nuts with the towel to remove the loose skins.