Ingredients:

3 Tbsp. melted unsalted butter, plus more room temperature for pan
1 large egg
Zest of 1 orange
½ cup fresh orange juice
2 cups milk
⅓ cup pure maple syrup
1 tsp. vanilla extract
1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt
1 tsp. ground cinnamon
½ tsp. ground ginger
2 cups old-fashioned oats
½ cup steel-cut oats
1 cup grated apple (about 1 medium)
1 cup grated carrot (about 1 large)
½ cup golden or other raisins
1 tsp. baking powder
½ cup chopped pecans, plus more for serving
Heavy cream or milk

Method:

Step 1
Place a rack in middle of oven; preheat to 375°. Butter an 8×8″ ovenproof baking dish. Whisk egg, orange zest, orange juice, milk, maple syrup, melted butter, vanilla, salt, cinnamon, and ginger in a large bowl to combine. Add old-fashioned oats, steel-cut oats, apple, carrot, raisins, baking powder, and ½ cup pecans and stir again to combine. Scrape into prepared baking dish and sprinkle more pecans on top.

Step 2
Bake oatmeal until top is golden brown and has puffed up a bit, about 40 minutes. Let sit 5 minutes.

Step 3
Serve warm with a drizzle of cream on top.

Do ahead: Oatmeal can be baked 5 days ahead. Cover and chill. Reheat with a splash of milk before serving.