Preheat the oven to 350°F.
In a food processor, combine the toasted nuts, 2 tablespoons of sugar, cinnamon and salt and pulse until finely chopped, about 8-10 times, leaving some of the nuts in larger pieces for texture.
Brush a 9x13-inch baking pan generously with some of the melted butter. Place 1 sheet of phyllo on the bottom of the prepared pan and trim it to fit. Trim the remaining sheets to about the same size with a sharp knife or scissors. Brush generously with melted butter and repeat with 8 more sheets of phyllo, gently pressing each layer. Make sure you cover the stack of phyllo with a damp towel at all times to prevent it from drying out. Sprinkle with about 1 cup of prepared nuts evenly. Top the nut mixture with a phyllo sheet and brush it generously with butter. Repeat with 5 more buttered phyllo sheets. Repeat with another cup of the nut mixture.
Top with another 5-7 phyllo sheets, brushing each sheet generously with butter.
Using a sharp knife, cut the phyllo layers into 24 (about 2 1/4-inch) squares. Cut each square in half on the diagonal. Bake until golden brown, 40 to 45 minutes. Set the baklava pan on a wire rack.
Meanwhile, make the syrup while the baklava bakes (The syrup should be ready when the baklava comes out of the oven.) In a medium saucepan, combine the sugar, honey, 1 cup of water. Bring the mixture to a boil over medium-high heat, stirring occasionally. Reduce the heat to medium-low and simmer, stirring occasionally, until slightly thickened, about 10 minutes. Remove from the heat and stir in the orange juice, orange zest and blossom waters if using.
Slowly pour the hot syrup all over the hot baklava carefully, covering the entire surface. Sprinkle the 3 tablespoons of chopped toasted pistachios on top. Let stand at room temperature on a wire rack at least 4 hours or up to overnight before serving. Store in an airtight container at room temperature for up to 3 days or in the fridge for up to a week. I like to warm it for few seconds in the microwave before eating.