To save time, buy good-quality store-bought puff pastry to make these easy, elegant party appetizers.
Line two baking sheets with nonstick baking mats; set aside.
In a small bowl, mix together both cheeses and cayenne pepper, if using. Sprinkle cheese mixture on work surface; top with puff pastry and roll out to a 10-by-13-inch rectangle, pressing dough into cheese to adhere. Sprinkle top of dough with poppy seeds, if desired; press gently with a rolling pin to adhere.
Using a pastry cutter, trim sides to form a 9-by-12-inch rectangle. Cut puff pastry into 3/4-inch-thick strips. Grab each end of a dough strip with your fingers and carefully stretch and twist strip in opposite directions; arrange 1 1/2 inches apart on prepared baking sheets. Transfer to refrigerator to chill, about 45 minutes.
Preheat oven to 375 degrees.
Transfer baking sheets to oven and bake until golden and puffed, 20 to 25 minutes. Transfer to a wire rack to cool.