Dissolve instant dashi in 1/4 cup of water in a medium bowl.

Whisk in gochujang, honey, rice vinegar, soy sauce, and sesame oil to create the glaze.

Cook rice cakes in a large pot of salted boiling water until al dente, about 3 to 4 minutes.

Drain the rice cakes well and rinse under cold water.

In a large bowl, toss the rice cakes with cubed Spam, quartered shallots, zucchini pieces, bell pepper pieces, and canola oil. Season with salt.

Thread the rice cakes, Spam, shallots, zucchini, and bell pepper alternately onto eight 14-inch metal skewers.

Light a grill and preheat to moderately high heat.

Grill the skewers, turning once, until the rice cakes are lightly browned and the vegetables are slightly softened, approximately 8 minutes.

Baste the skewers with the prepared gochujang sauce.

Continue grilling, basting frequently, until the skewers are glazed and slightly charred, about 5 minutes longer.

Transfer the skewers to a work surface and brush with additional gochujang sauce.

Arrange the glazed skewers on a serving platter and garnish with black sesame seeds, chopped cilantro, and crushed peanuts.

Serve the skewers warm, and offer any remaining gochujang sauce at the table.