Preheat your oven to 350℉. Grease or spray a 9x13 inch baking pan with butter.
Syrup:
In a medium pot, add the sugar, water, lemon peel and cinnamon stick. Bring to an almost boil, then lower to a simmer and cook your syrup for 10 minutes. Remove from heat and stir in the honey. Now let the syrup cool.
Filling:
In a small food processor or by hand, chop your walnuts into small crumbs. Mix them with the sugar and cinnamon.
On a large clean surface, open your phyllo package and lay out the sheets flat, covered by a clean cotton towel (if you don't cover the stack, the phyllo will get dry). Take one sheet at a time and brush it with the melted butter, then sprinkle on small amount of the walnut filling here and there - about 1-2 tbs per sheet. Use your fingers to crinkle the sheet like an accordion. Transfer the sheet to your baking dish. Repeat this step for all the phyllo sheets until your baking dish is full - packing them in as you go. Take the remaining butter and brush the top of the pie. Bake for 20 minutes.
Custard:
Whisk together the eggs, milk, sugar and cinnamon. EVENLY pour it over the baklava and place bake in the oven for another 25-35 minutes or until the top is golden brown.
Once you remove the baklava from the oven, pour the cooled syrup over the hot baklava. Then sprinkle on the pistachios immediately. Allow the syrup at least an hour to soak in prior to serving.
Notes
Follow the phyllo sheets package instructions for thawing.Refrigerate leftovers.