Heat the oven to 375°F. Lightly grease 8 cups of a standard muffin pan.
In a large bowl, combine the ground beef, panko, egg, most of the sliced scallions, ginger, garlic, 1 tablespoon of the soy sauce, and 1 teaspoon of the gochujang. Mix gently just until combined.
Divide the mixture among the 8 prepared muffin cups. Press it in lightly, leaving the tops slightly rounded rather than packing the meat tightly.
In a small bowl, stir together the ketchup, honey, rice vinegar, sesame oil, remaining 1 tablespoon soy sauce, and remaining 2 teaspoons gochujang.
Spoon about half of the glaze over the meatloaf muffins. Bake until the centers reach 160°F, about 20 to 25 minutes.
Spoon the remaining glaze over the muffins. Let them rest in the pan for 5 minutes, then carefully remove them. Finish with the sesame seeds and the reserved scallions.