Defrost phyllo according to manufacture's instructions and bring to room temperature before using.
Preheat Oven / Prepare pan
Preheat oven to 325℉.
Generously grease inside of 10" springform pan with olive oil spray (alternatively, brush with melted butter or olive oil).
Prepare Walnut Filling
Combine walnuts, cinnamon, brown sugar and honey in a bowl. Set aside.
Prepare Pumpkin Filling
Add pumpkin puree, eggs, brown sugar, milk, cinnamon, ginger and nutmeg in a bowl. Whisk until smooth. Set aside.
Assemble Phyllo
Take one sheet of phyllo dough and place on a surface - be sure to replace damp towel over remaining pieces. Spray lightly with olive oil. Sprinkle 1 teaspoon of granulated sugar over the dough.
Add another sheet of phyllo dough to the top of the sheet you just worked on. Spray lightly with olive oil.
Carefully pick up dough and place it in prepared springform pan leaving ends of phyllo hanging over the sides. Gently press the dough into the bottom and up the inside of pan.
Take another sheet of phyllo dough and place on a surface. Spray lightly with olive oil. Sprinkle 1 teaspoon of granulated sugar over the dough. Add another sheet of phyllo dough to the top of the sheet you just worked on. Spray lightly with olive oil.
Carefully pick up dough and place it in pan over the first piece so it forms a cross. Gently press the dough into the bottom and up the inside of pan.
Repeat the process of adding sheets of phyllo to the pan 3 more times, continuing to crisscross the dough in pan (you will use a total of 10 sheets to line the pan).
Assemble Filling and topping
Pour walnut mixture into springform pan on top of phyllo dough. Spread evenly on the bottom taking care not to rip dough.
Pour pumpkin mixture over walnuts. Spread evenly.
Fold phyllo hanging over the edges into the pan and over filling.
Spray 4 remaining phyllo sheets with olive oil and sprinkle with 1 teaspoon granulated sugar. Pick up each sheet individually and scrunch together loosely. Place on top of pumpkin mixture randomly to cover filling.
Bake and Serve
Bake in preheated 325℉ oven for 45 - 50 minutes. The top will be golden brown.
Remove from oven and place on a wire rack. Drizzle ½ cup honey over top of baklava while still hot.
Cool for 2 hours, remove from springform pan and carefully place on a serving platter.