1. Prepare the Crust:

1. Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.
2. In a saucepan over medium heat, combine heavy cream, cornstarch, garlic powder, smoked paprika, salt, and pepper. Whisk until smooth and slightly thickened.
3. Reduce heat to low and gradually add shredded Gruyere and cheddar cheese, stirring until fully melted and smooth. Remove from heat and let cool slightly.
4. Roll out the puff pastry sheet and cut into long strips. Wrap strips around a cylindrical mold (like a candle holder) to form a candle shape, leaving the top open. Brush with egg wash.
5. Bake the puff pastry for 15-20 minutes until golden brown. Remove from oven and let cool slightly before carefully removing the mold.
6. Fill the puff pastry candle with the warm cheese fondue just before serving. Serve immediately.