In a small saucepan over medium-low, melt the butter. Remove from the heat and cover to keep warm. In a food processor, pulse 216 grams (1½ cups) pistachios to create a mixture of finely and coarsely ground nuts, about 15 pulses. Transfer to a mesh strainer set over a medium bowl; shake to sift out the pistachio “dust.” Do not wash the food processor bowl and blade. Measure 1½ to 2 tablespoons of the dust into a small bowl or ramekin and set aside. If the pistachios in the strainer are still very large, transfer to a cutting board and use a chef’s knife to chop them into bits no larger than ¼ inch. Transfer the pistachios to the bowl into which the dust was sifted.

In the now-empty processor, combine the remaining 144 grams (1 cup) pistachios and 1 tablespoon sugar; pulse several times to roughly chop the nuts, then process until very finely ground, 1 to 1½ minutes, scraping the bowl as needed. Transfer to a small bowl.

Heat the oven to 450°F with a rack in the lowest position. Cut a 9-inch round of kitchen parchment; set it aside. Brush the bottom and sides of a conventional (not nonstick) 9-inch cake pan with melted butter.

If using 13-by 18-inch phyllo sheets, cut the stack in half crosswise, then stack the two piles on top of each other. If using 9-by-14-inch sheets, leave them in a single stack. Working quickly, place the cake pan on top of the phyllo and, while holding it in place, use a sharp knife and the bottom of the pan as a guide to cut the phyllo sheets into a stack of 9-inch rounds. Identify the 2 most perfect rounds and set them on a large plate, then stack 6 more rounds on top. Cover with plastic wrap, place the remaining phyllo rounds on top of the plastic and cover with another sheet of plastic wrap. Discard the phyllo scraps. If the butter has solidified, rewarm it.

Place 1 of the top phyllo rounds in the prepared cake pan and lightly brush it with melted butter. Repeat the layering and brushing until you have used all of the phyllo rounds down to the bottom layer of plastic wrap; it is fine if some of the phyllo rounds are torn or creased. You will have a placed about 10 phyllo rounds in the cake pan. Evenly sprinkle on the coarsely chopped pistachios, then drizzle with about 1 tablespoon melted butter.

Uncover the bottom stack of phyllo rounds. Lay a round on the nut layer and brush with butter; repeat with another phyllo round. Evenly sprinkle with one-third of the finely chopped pistachios. Place another 2 phyllo rounds on top, brushing each with butter, then evenly sprinkle with half of the remaining finely chopped pistachios. Place another 2 phyllo rounds on top, brushing each with butter, then evenly sprinkle with the remaining finely chopped pistachios. Drizzle with about 1 tablespoon melted butter, then place the penultimate phyllo round on top. Brush with butter, then lay on the final phyllo round but do not brush it with butter.

Lay the plastic wrap used to cover the phyllo directly against the surface of the baklava, and, with your hands, smooth and compress the layers, including the edges. Remove the plastic, then drizzle on about ¼ cup of the remaining melted butter and brush evenly over the surface.

Using a serrated knife or a sharp chef’s knife, gently score the baklava in half, then score evenly spaced parallel cuts on each side of the center line, creating four strips of even width. Now do the same at a right angle to the first cuts, forming a grid. You will have 4 small triangular shapes (1 in each quadrant of the circle) and 12 square/squarish shapes. Score the 12 square/squarish pieces in half on the diagonal; you will now have a total of 28 pieces.

With a small, sharp paring knife, retrace the scored cuts, this time cutting all the way through the bottom layers of phyllo, using a sawing motion if needed. Replace any pieces of phyllo that were displaced during cutting. Using your fingers, lightly flick water onto the baklava. Lay the reserved parchment round directly against the surface of the baklava; if the parchment curls, gently crumple it, then flatten it with your hands. Bake until the top of the baklava is golden brown, 17 to 20 minutes.

Meanwhile, in a small saucepan, combine ½ cup water, the sugar, zest strips and a pinch of salt; bring to a boil, then reduce to medium-low and cook, stirring, until the sugar dissolves. Remove from the heat and stir in the lemon juice. Cover and let stand until ready to use.

Set the cake pan on a wire rack; remove and discard the parchment round. Immediately remove and discard the zest strips from the syrup, then slowly pour the syrup over the baklava. Sift on the reserved pistachio dust, evenly covering the surface, then cool completely. Before serving, use the paring knife to retrace the cuts to ensure the pieces can be removed easily.