Rinse 2 cups of Calrose rice under cold water until the water runs clear, then cook according to the package instructions. Let it steam for 5-10 minutes after cooking.

In a microwave-safe bowl, whisk together 1/4 cup dark brown sugar, 1/4 cup soy sauce, 2 tablespoons mirin, and 1 teaspoon sesame oil. Microwave until the sugar dissolves.

Lightly spritz a skillet with nonstick spray, heat over medium-high, and fry 8 slices of the Spam for 2-3 minutes each side until golden brown, brushing teriyaki sauce over each slice.

Lay a piece of sushi nori rough side up on plastic wrap, place the musubi mold at one end, ready for assembly.

Spoon a layer of rice into the mold, sprinkle furikake over it, add teriyaki-glazed Spam slices, and press down firmly again.

Lift the nori and fold it over the Spam and rice, moistening the edges of the nori to seal it closed.

Using a sharp, wet knife, slice the finished Spam Musubi in half crosswise to expose the layers. Serve as a snack or lunch.