Begin by slicing your spam into 6-8 pieces about ¼ inch thick (or thicker if you would like). 

Add your soy sauce, sugar, and fish sauce or oyster sauce into a small bowl, and mix it until it is fully incorporated. Set the sauce to the side. 

Heat up a skillet over medium high heat. Add your sliced spam into the skillet in one single layer. Fry it on each side for about 2-3 minutes,or until it begins to brown and form a crust. 

Once both sides are fried, gently pour the sauce directly into the skillet with the spam. Continue to cook it for another two to three minutes, turning the spam to coat it in the sauce ensuring each piece is covered. 

Once the spam is coated in the sauce and it begins to reduce, remove the skillet from the heat. 

Use kitchen shears to cut the nori sheets into thin pieces; about 2-3 inches wide. You can either cut them in half, or cut them in thirds. 

Place your thin nori sheet on a clean dry surface, place a musubi mold directly over the nori seaweed, add a thick layer of rice, and then top it with a piece of spam. Press the spam and rice down firmly.

Remove the rice and spam mixture from the musubi mold, and wrap the nori around it as tight as possible. Use a few pieces of the cooked sushi rice to help seal the edges together. 

Repeat these steps until each piece of spam is used. Serve immediately and enjoy!