Step 1

Preheat oven to 300°F. Bring sugar and 1 cup water to a boil in a small saucepan over medium-high; reduce heat to medium-low, and cook, stirring occasionally, 10 minutes. Stir in lemon juice; cook, stirring occasionally, 10 minutes. Remove from heat; let cool to room temperature, about 1 hour.

Step 2

Meanwhile, bring butter to a boil in a small saucepan over medium-high. Reduce heat to medium; cook, skimming and discarding milk solids, until clear, about 15 minutes. (You should have 1 ½ cups clarified butter.) Set aside. Place nuts in an even layer on a large rimmed baking sheet; bake in preheated oven until lightly toasted, about 10 minutes, stirring halfway through. Let cool completely at room temperature, about 30 minutes. Increase oven temperature to 325°F.

Step 3

Unroll phyllo dough, and lay on a clean, dry towel; cover with wax paper or parchment paper and a damp towel. Working with 1 phyllo sheet at a time, place on a work surface with 1 short side facing you; brush lightly with about 1 teaspoon clarified butter. Starting at short edge, make a 2-inch fold; sprinkle about 1 tablespoon cooled walnuts over entire dough sheet. Place a dowel or wooden skewer horizontally in middle of fold. Tightly roll dough over dowel until all phyllo dough is wrapped around dowel. Holding dowel ends and rolled dough, gently squeeze both ends toward center, similar to threading a curtain on a curtain rod, crinkling the bourma until it is about 5 inches long. Remove dowel from dough; place scrunched pastry, seam side down, on a large rimmed baking sheet. Repeat with remaining phyllo, about 1 cup clarified butter, and remaining walnuts, placing on baking sheet touching other bourma.

Step 4

Brush tops of bourma evenly with remaining clarified butter. Bake at 325°F until golden brown, about 30 minutes. Let bourma cool on baking sheet on a wire rack about 15 minutes. Drizzle with sugar syrup before serving.