Preheat oven to 350 degrees F.
Finely chop the nuts in a food processor or coffee grinder. Transfer nuts to a bowl and mix in brown sugar, ground cinnamon, and cloves.
Brush a 13 by 9-inch baking pan with melted butter and set aside. Cut a piece of cardboard into a 13 by 9-inch rectangle. Unroll the phyllo dough and lay the sheets flat on a work surface. Set the cardboard template on the stack of phyllo and trim the excess so they fit the pan. Keep the pastry covered with a damp, not wet, towel as you work to prevent drying out.
To build the baklava, you will alternate 3 layers of dough with 2 layers of nuts. Start with a stable base of 8 sheets on the bottom, brushing each with melted butter. Spread 1/2 the nut mixture evenly over the stacked sheets. Cover with 4 sheets of phyllo, painting each with melted butter, then sprinkle again with remaining nut mixture. Top the last layer of nuts with 8 layers of phyllo as you did for the bottom. Drizzle any remaining butter over top.
If you have time, cover and refrigerate for 30 minutes so the butter will set and make the baklava easier to cut. Using a sharp knife, make 5 cuts across lengthwise, then cut diagonally to form diamonds. Baklava is more difficult to cut after it is cooked because the pastry becomes so flaky. Bake for about 40 minutes until golden and flaky. If the top browns too quickly during baking, tent with foil.
To make the syrup: combine the ingredients in a saucepan and bring to a boil. Reduce the heat and let simmer for 10 minutes until thickened. Remove the orange peel, cinnamon stick, and whole clove; set aside to cool.
Remove an end piece of the baklava and tilt the pan to allow the butter to collect in the corner. Spoon out the excess and discard. With the pan flat, pour the syrup evenly over the hot baklava. Allow to stand for several hours before serving.