1. Cut the pumpkin flesh into very small dice and place in a small saucepan. Pour in enough water to barely cover, and bring to a boil. Reduce the heat to low, cover, and simmer for 5 minutes, or until tender. Drain and let cool.
2. Preheat the oven to 350°F (180°C). Mix the pumpkin, feta cheese, raisins, and cinnamon, and season with the pepper.
3. Stack the filo sheets on top of each other and cut the stack into 4 long strips, about 3in (7.5cm) wide for a total of 24 strips. Cover the strips with moistened paper towels.
4. Lightly dust a baking sheet with flour. Working with 1 strip at a time, brush the strip with butter. Place a heaping teaspoonful of the pumpkin and cheese mixture about 1in (2.5cm) from the bottom end. Fold over a corner of the strip diagonally to cover the filling and form a triangular pocket of filled pastry. Working upward, keep folding diagonally, from one side to the other, to retain the triangular shape, until all the pastry is folded, making sure any gaps in the pastry are pressed closed. Transfer the triangle to the baking sheet and cover with a damp paper towel. Repeat with the remaining ingredients.
5. Butter another large baking sheet. Arrange the triangles on the buttered sheet. Brush with the remaining melted butter. Bake for about 20 minutes, or until crisp and golden. Serve hot or warm.
Cheese and Potato Pastries: Substitute finely diced potato or sweet potato for the pumpkin.