Use rolled oats and a shallow dish
Old-fashioned rolled oats are the intended starting point. Steel-cut oats need a different amount of liquid and a different cooking method; do not substitute them directly. Use an 8-inch square baking dish so the center is not much deeper than the edges. Grease the dish lightly before mixing.
Dice the apple evenly
Wash, core, and cut the apple into small pieces, about ¼ inch across. Peeling is optional, but large strips of peel can be more noticeable in a soft bake. Distribute the pieces through the oats so each portion gets some fruit instead of a dense layer at the bottom.


Check the center before resting
Oven temperatures and baking dishes vary. Look for a center that no longer ripples with liquid, then use a food thermometer to check that the egg-containing mixture has reached 160°F. Allow 10 minutes of rest before portioning. The oats continue to absorb moisture while cooling; a soft texture is expected.
Plan breakfast portions safely
Serve with additional milk or yogurt if desired, measured separately. Refrigerate leftovers in shallow containers within 2 hours, or 1 hour when the room exceeds 90°F. Keep at 40°F or below and use within 3 days. Reheat individual portions to 165°F. Freeze cooled portions for about 1 month for quality and thaw in the refrigerator. Do not leave this egg-and-milk mixture on the counter overnight.
OUBELLA KITCHEN
Apple Cinnamon Baked Oatmeal with Rolled Oats
Ingredients
Amounts scale; cooking times do not.
Instructions
Notes
Estimated preparation: 15 minutes; cooking: 40 minutes; total: 65 minutes, including any resting or chilling. This recipe has not been kitchen-tested. All timings are estimates. Contains eggs and milk. Oats may have wheat cross-contact; check labels.
Times vary with equipment. Editorial approach.