Roughly chop the cold leftover pasta. A pair of kitchen scissors works great for this!
In a bowl, combine the chopped pasta, eggs, 1 1/4 cups panko breadcrumbs, and grated Parmesan cheese. Season generously with salt and pepper.
Mix everything well. Test by scooping a small amount and gently flattening it. If it doesn't hold its shape, add a bit more panko breadcrumbs until it does.
Heat 2 tbsp of olive oil in a large non-stick skillet over medium-high heat until shimmering.
Scoop about 1/3 cup of the pasta mixture per fritter, packing it well into the scoop. Gently release the mixture into the hot oil, using the scoop to flatten them into about 1 cm (2/5 inch) thickness. Cook in batches, ensuring not to overcrowd the pan.
Fry the first side for about 2 minutes, until deep golden brown and crispy. Carefully flip the fritters and cook the second side for another 1 to 1.5 minutes until equally crispy.
Remove the fritters from the pan and place them on a plate lined with paper towels to drain any excess oil.
Serve immediately while hot and crispy. Garnish with fresh parsley and extra Parmesan if desired!