1. Preheat the oven to 350°F (175°C). Lightly grease a 9 x 13-inch baking dish.

2. Carefully unroll the thawed phyllo dough and keep the sheets covered with a clean, slightly damp kitchen towel while working.

3. Take one phyllo sheet and gently gather it from the short ends to create loose accordion-style folds. Place the crinkled sheet into the prepared baking dish.

4. Repeat with the remaining phyllo sheets until the dish is filled with loose crinkled folds.

5. Drizzle the melted butter evenly over the phyllo, using a pastry brush if needed to distribute it through the folds.

6. Bake the buttered phyllo for about 10 minutes, until it begins to turn lightly golden and crisp.

7. While the phyllo bakes, whisk together the eggs, milk, granulated sugar, vanilla extract, and baking powder until smooth.

8. Remove the partially baked phyllo from the oven and slowly pour the custard mixture evenly over the crinkled layers.

9. Return the dish to the oven and bake for 30–35 minutes, or until the pastry is deeply golden and the custard is set.

10. While the cake bakes, combine the sugar, water, and vanilla extract in a small saucepan. Bring to a gentle simmer and cook until the sugar has completely dissolved.

11. Remove the syrup from the heat and let it cool slightly.

12. Pour the warm syrup slowly over the freshly baked Crinkle Cake, allowing it to settle into the folds.

13. Let the cake rest before slicing and serving.