Make the maple marinade by mixing all ingredients together. Wash Brussels sprouts, halve them, and toss in marinade. Marinate overnight for the best results or at least 2 to 3 hours.
Preheat oven to 400 degrees F.
Bake Brussels sprouts with flat side face down on medium-sized sheet pan for 25 minutes, or until caramelized. While Brussels sprouts cook, make gochujang mayo. Combine all ingredients in bowl and transfer to squeeze bottle or piping bag.
In small saucepan, heat the vegetable oil over medium heat. Test to see if oil is hot enough by carefully dropping in 1 shallot. If it sizzles, add the rest and let cook until light brown (about 5 to 10 minutes).Transfer to paper towels with slotted spoon to remove excess oil.
After the Brussels sprouts are done baking, transfer to serving plate. Drizzle with gochujang mayo and top with kimchi, fried shallots, green onions, and sesame seeds. Serve immediately.