Prepare the pineapple fried rice. Heat 1 tablespooon oil in a saute pan or wok over medium-high heat. Saute the shallots and garlic until aromatic, about 1 minute. Add the pineapple and cook until softened, about 3 minutes. Add the rice, breaking it up as it reheats. Season the rice with soy sauce, fish sauce, curry powder, and sugar, stirring until well combined. Remove from heat and stir in the chopped cilantro. Let cool slightly.
Prepare spam. Combine water with soy sauce and sriracha in a small bowl. Set aside.
Heat a medium pan over medium-high heat. Lay spam in an even layer and cook until browned and crispy on the edges, about 2 minutes. Flip and sear on the other side.
Reduce heat to medium-low. Sprinkle 1 tablespoon sugar evenly over both sides of the spam. Pour in soy sauce mixture and swirl the sauce, flipping the spam to evenly distribute. Simmer until the sauce dissolves, about 4 minutes, flipping the spam over halfway through. Remove from heat and keep warm.
Cook the eggs. Whisk together the eggs with water, salt, dashi powder, and white pepper. Heat 1 tablespoon oil in a large 12-inch nonstick saute pan over medium heat. Add the eggs and cook until the eggs have set. Remove from heat and cut into 6 pieces the same size as the spam.
Assemble the musubi. Use a musubi mold and place it on top of a cut sheet of nori. Press about ⅓ cup of the pineapple fried rice in the bottom. Lay a piece of egg on top followed by a slice of spam. Remove the mold and wrap the nori around the spam, egg, and fried rice. Repeat with the remaining musubi. Serve immediately.
Notes
The rice, spam, and eggs can be cooked ahead of time. Reheat the items before assembling the musubi.