Preheat oven to 375 degrees F. Coat a square baking dish with cooking spray. Prepare corn muffin batter according to package instructions. Stir thawed corn into batter. Bake for 15 minutes or until a toothpick inserted in the center comes out clean. Let cool.
Cook bacon until crisp. Reserve the bacon drippings. Crumble bacon once cool.
Place Brussels sprouts on a baking sheet and toss with bacon drippings, salt, pepper and nutmeg. Roast for 15-20 minutes.
Break corn muffins into bite-sized pieces and place on a baking sheet. Bake for 12-15 minutes, stirring occasionally, until golden brown and crispy.
Meanwhile, add onion to pan and cook over medium-high heat until caramelized.
Just before serving, toss Brussels sprouts with 3/4 of the crumbled bacon, caramelized onions and corn muffin crumbs. If desired, use chicken stock to moisten mixture. Pour into a serving bowl and garnish with remaining crumbled bacon.