For the syrup:
3/4 cup sugar
3/4 cup water
3/4 cup honey
1. Prep the filling. Preheat the oven to 350°F. Measure out 8 ounces of walnuts and 8 ounces of pistachios using a kitchen scale and place in the bowl of a food processor (reserve the additional 1/4 cup of pistachios for garnish). Add the sugar and cinnamon. Pulse a few times to break up the nuts, but do not chop them too fine or into a powder. Transfer to a bowl.
2. Melt the butter. Place the two sticks of butter into the saucepan and melt under low heat. Keep an eye on things and turn off the burner when the sticks are nearly melted. The rest will melt from the residual heat of the pan.
Set up your assembly area. Clear off a large surface, such as your kitchen table or counter. Place the bowl of nut filling, the baking pan, the melted butter, and the pastry brush on the surface, reserving a spot for the phyllo.
3. Set up the phyllo. Unwrap the phyllo sheets and carefully unroll onto the assembly surface, keeping the large sheet of plastic used to roll the sheets underneath. Dampen the tea towel (not too wet!) and lay it over the phyllo.
Trim the phyllo (optional). If the phyllo dough is too big for your baking pan, trim the phyllo sheets to match the dimensions of your pan. A pair of scissors is the easiest way to do this.
4. Lay the bottom layer. Using the pastry brush, brush on a thin layer of butter all over the bottom of the baking pan. Fold back the tea towel, carefully remove one sheet of phyllo dough, and place it on the bottom of the pan. Butter the top of the phyllo lightly, making sure you are going out all the way to the edges. Repeat with layering 6 more sheets to total 7 sheets of phyllo, buttering the top of each sheet of phyllo before placing the next. Be sure to re-cover the remaining phyllo with the tea towel each time you remove a sheet.
5. Add the first layer of nuts. Sprinkle half the nuts over the phyllo and spread them gently with your hand so that you have a fairly even layer. Be sure to spread them all the way to the edges.
Create another phyllo layer. Place a sheet of phyllo on top of the nuts and carefully brush with melted butter. Repeat, layering 4 more sheets in all, with butter between each layer.
6. Add the second layer of nuts. Sprinkle the remaining layer of nuts over the phyllo. Again, spread them into an even layer and push them all the way to the edges.
7. Lay the top layer. Place a phyllo sheet on top of the nuts and brush lightly with butter. Repeat, layering 6 more sheets of phyllo, with butter between each layer, to total 7 sheets.
8. Cut the baklava. Using a very sharp knife, cut the baklava on the diagonal into approximately 28 pieces (can be more if you make smaller pieces).
Bake. Place the pan of baklava in the oven and bake for about 45 minutes.
Check half way through and rotate the pan for even browning.
Chop the pistachios. While the baklava is baking, finely chop the remaining 1/4 cup of pistachios and set aside.
Remove the baklava from the oven and cool. When the phyllo is evenly golden-brown all over, remove the pan from the oven and set on a rack to cool.
Make the syrup. While the baklava is cooling, make the syrup. Combine the sugar, water, and honey in a saucepan and bring to a boil. Boil for 10 minutes.
Re-cut the baklava. While the syrup is cooking, run your knife through the baklava to be sure the pieces are cut all the way through.
Pour on the syrup. When the syrup has boiled for 10 minutes, remove from the stove and carefully pour over the baklava, being sure to coat each piece.
Garnish and serve! Sprinkle some of the chopped pistachios on each of the baklava squares. Cover the baklava and let sit for several hours or overnight before serving. Will keep for up to 5 days, covered.