Cook spaghetti according to package instructions and set aside.
If using frozen shrimp, unfreeze them by dipping them in a bowl with cold water.
Prepare the shrimps by removing their shells leaving only one shell next to their head and one shell at their tail to hold them in place. Cut their mustaches with a scissor. Season with salt and pepper.
Heat a good splash of olive oil in a large skillet over high heat.
Cook the shrimps for 2 minutes on each side. Remove from heat and set aside.
OPTIONAL: You may add a drop of brandy, or ouzo to the shrimps at this point, and wait until it evaporates or light it on fire.
In the same skillet add the onion, garlic, and peppers and cook until softened. Add the tomatoes, sugar and a pinch of salt and pepper. Reduce heat to medium and cook while stirring occasionally until thick sauce forms. Takes about 15-20 minutes.
Add a splash of water and cook for 5-10 minutes more. Taste the sauce to see if it needs any more salt and pepper.
Add the fresh parsley and shrimps in the sauce and cook for 3-4 minutes.
Stir in the cooked pasta and cook for a minute more. Remove from heat and serve!