Preheat oven to 425°F. Line baking sheet with parchment paper; set aside.

On lightly floured work surface, roll out one sheet of puff pastry into 10-inch square; cut into 4 rectangles. Spread half of the pesto over each rectangle; cut each piece diagonally to create 8 triangles. Repeat with second sheet of puff pastry.

Place halved Pepperoni Panino on wide base of each triangle; fold over ends and roll up, pinching seams tightly to seal.

Place, seam side down, about 1 1/2 inches apart on prepared baking sheet; refrigerate for 15 minutes. Meanwhile, whisk egg with 1 tbsp water; brush over tops. Sprinkle with Parmesan. Bake in center of oven for 15 to 20 minutes or until golden.

Tip: These rolls can be assembled ahead, covered and refrigerated for up to 1 day.