Cook syrup:
1. Combine all syrup ingredients except the ouzo in a medium saucepan, bring to a boil and stir to dissolve sugar.
2. Reduce heat and simmer until thickened, about 20 minutes.
3. Remove from heat, add ouzo and allow to cool.
4. Remove lemon and cloves.
Create filling:
1. Place all ingredients in a food processor fitted with a metal blade.
2. Pulse several times until nuts are finely chopped.
Assemble baklava:
1. Butter a 10x13 inch rectangular baking dish.
2. Unfold phyllo from package and cut dough in half (each half sheet should then fit in baking dish).
3. Layer 2 sheets of phyllo into dish, keeping unused phyllo covered with a slightly damp towel.
4. Brush layer with melted butter.
5. Continue until 10 sheets have been used.
6. Spread 1/3 of the filling over the top.
7. Continue making 2 more 10 sheet layers, similar to above, placing nuts between the layers and on top.
8. Drizzle top with remaining butter.
Bake:
1. Trim away excess phyllo from edges of pan as necessary and cut into small squares or diamonds before baking.
2. Bake until pastry is golden brown and crispy, about 1 hour.
3. Remove and let cool for 30 minutes.
Finish and serve:
1. Pour cooled syrup over warm pastry and allow to soak in.
2. Cool and serve at room temperature.