Prepare the Batter
In a large mixing bowl, combine hondashi with 1 cup of water and whisk until fully dissolved. Add the eggs, whisking until smooth. Gradually incorporate the flour, salt, baking powder, and baking soda, mixing until a uniform batter forms. Gently fold in the shredded cabbage, sliced scallions, and pickled ginger, ensuring they are evenly distributed.
Cook the Pancakes
Heat 2 tablespoons of oil in an 8-inch nonstick skillet over medium-low heat. Pour half of the batter into the skillet, spreading it into an even 6-inch round, about 1-inch thick. Arrange half of the pork belly over the batter, slightly overlapping the pieces. Allow the pancake to cook for 8-10 minutes, or until the bottom is golden brown and set. Reduce the heat to low, then carefully flip the pancake by inverting it onto a plate and sliding it back into the skillet.
Finish Cooking
Cook the pancake for an additional 8 minutes, until the second side is golden brown and the center is fully cooked. Once done, transfer the pancake to a large plate with the pork side facing up. Wipe the skillet clean and repeat the process with the remaining oil, batter, and pork belly.
Serve and Garnish
Drizzle the finished pancakes with okonomi sauce and Kewpie mayonnaise. Top with a generous sprinkle of shaved bonito and shredded nori. Serve immediately while warm for the best flavor and texture.