Preheat oven to 350 °F
Bring honey, cinnamon sticks, 1 c sugar, and 1 c water to a boil in medium heavy saucepan over med-high heat, stirring until sugar dissolves.
Reduce heat to medium and continue to boil until syrup is reduced to about 1.5 c, 15-18 mins.
Transfer to a. medium bowl, stir in bourbon, and let cool.
Spread pecans on large rimmed baking sheet and toast until golden brown, 13-15 mins. Let cool.
Transfer nuts to a food processor. Add ground cinnamon, 1 tsp orange zest, and remaining 1/2 c sugar. Pulse until coarsely chopped.
Place a stack of phyllo sheets on a work surface. Using base of springform pan as a guide, and starting at edge of phyllo, carefully cut out 20 (9″) circles, leaving as much phyllo remaining as possible. Cover phyllo circles. Using base of pan as a guide, cut remaining phyllo into 20 (4 1/2″) half circles.
Insert base into pan and secure the latch. Brush base with butter. Place 1 phyllo circle in pan and brush generously with butter. Top with 2 half-circles to create a full circle, brush with butter. Top with full circle, brush again. Top with 2 more half-circles at a 90° angle from the first half-circle layer, brush with butter. Top with a full circle, and brush again. You should have 5 layers of pastry (full circle – half-circles – full circle – half circles – full circle), with butter spread between each layer. Spread one-fifth of nut mixture over phyllo. Repeat layering 4 more times. Top with the 5 remaining phyllo circles; brush top with butter.
Using a sharp knife, score the top layer (do not cut through to bottom of pan) to divide into 4 quadrants.
Working with 1 quadrant at a time, make 1 straight cut to divide the quadrant into 2 even wedges. Make 4 more straight cuts (2 each on either side of, and parallel to the quadrant division line), spacing evenly apart. Now working within each wedge, make 2 evenly-spaced cuts parallel to the outside edge of the quadrant, connecting at points with the previous cuts to form a diamond pattern. Repeat with the remaining quadrants to create a starburst pattern.
Transfer pan to a rimmed baking sheet and bake until phyllo is golden brown, about 45 minutes.
Spoon cooled syrup over hot baklava in 4 additions. Place orange curls on top. Let cool completely in pan. Remove springform ring and cut baklava along the scored lines.
