There are breakfast casseroles that require a dozen ingredients and complicated steps. And then there is this Amish Baked Oatmeal Casserole. With just six simple ingredients and almost no effort, you can create a hearty, wholesome breakfast that tastes like it came from a cozy Amish kitchen. Old-fashioned rolled oats are baked in a custard of milk, eggs, brown sugar, cinnamon, and salt until set and lightly golden. The result is a warm, comforting, lightly sweetened oatmeal that is perfect for feeding a crowd.
The beauty of this recipe lies in its simplicity. The oats provide fiber and heartiness. The milk and eggs create a rich, custardy texture. The brown sugar adds a deep, caramel-like sweetness. The cinnamon provides warmth and spice. This baked oatmeal is a blank canvas for endless toppings and mix-ins.
Perfect for busy mornings, holiday breakfasts, meal prep, or any time you need a warm, satisfying start to the day. Serve it with a splash of milk, fresh berries, chopped nuts, or a drizzle of maple syrup.
Why You’ll Love This Recipe
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Only 6 simple ingredients
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Hearty, wholesome, and filling
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Custardy texture with a lightly golden top
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Perfect for feeding a crowd
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Great for meal prep (reheats beautifully)
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A blank canvas for endless toppings
6-Ingredient Amish Baked Oatmeal Casserole
Prep Time: 10 minutes | Bake Time: 30-35 minutes | Resting Time: 10 minutes | Total Time: Approximately 50 minutes
Yield: 6 servings
Ingredients
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2 cups old-fashioned rolled oats
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2 cups milk (any dairy or unsweetened non-dairy)
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2 large eggs
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⅓ cup brown sugar, lightly packed
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1 teaspoon ground cinnamon
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½ teaspoon fine salt
Instructions
1. Preheat and Prepare:
Preheat your oven to 350°F (175°C). Lightly grease an 8×8-inch or similar-sized casserole dish with butter or neutral oil.
2. Add the Oats:
Spread the raw rolled oats evenly in the bottom of the prepared casserole dish. Use your hand or the back of a spoon to level them out so they bake uniformly.
3. Make the Custard:
In a medium mixing bowl, whisk the eggs until well broken up. Add the milk, brown sugar, cinnamon, and salt. Whisk until the sugar is mostly dissolved and the mixture looks smooth and evenly colored.
4. Pour Over the Oats:
Slowly pour the milk and egg mixture over the raw rolled oats, making sure to cover all the oats. Gently tilt the dish or nudge the oats with a spoon so everything is moistened and there are no dry pockets.
5. Let It Rest:
Let the mixture sit on the counter for about 5 minutes so the oats begin to absorb some of the liquid. This helps the baked oatmeal set nicely while still staying tender.
6. Bake:
Place the casserole dish on the center rack of the preheated oven. Bake for 30 to 35 minutes, or until the top looks set and lightly golden around the edges and the center no longer appears liquid when you jiggle the dish.
7. Rest and Serve:
Remove from the oven and let the baked oatmeal rest for at least 10 minutes before serving. This brief cooling time allows it to firm up so you can scoop or cut it cleanly. Serve warm, plain or with a splash of milk and any favorite toppings.
Recipe Notes & Pro Tips
Old-Fashioned Rolled Oats: Use old-fashioned rolled oats (not instant or quick-cooking). They provide the best texture—chewy and hearty, not mushy. Quick oats will result in a softer, less textured casserole. Steel-cut oats will not cook through in this time.
Milk: Any milk works. Whole milk provides the richest, creamiest texture. Low-fat or skim milk will result in a slightly less rich casserole. Unsweetened almond, oat, or soy milk works for a dairy-free version.
Brown Sugar: Light or dark brown sugar both work. Dark brown sugar has a higher molasses content, resulting in a deeper, richer flavor. For a less sweet version, reduce the brown sugar to ¼ cup.
Let It Rest: The 5-minute rest before baking allows the oats to absorb some liquid, which helps the casserole set properly. Do not skip this step.
Baking Time: Ovens vary. Start checking at 30 minutes. The casserole is done when the top is set and golden and the center is no longer liquid. Overbaking can make the oatmeal dry.
Make Ahead: Assemble the casserole the night before. Cover and refrigerate. In the morning, let it sit on the counter for 15 minutes while the oven preheats, then bake as directed (add 5-10 minutes to the baking time).
Double the Recipe: For a 9×13-inch dish, double all ingredients. Increase baking time by 10-15 minutes.
Variations
Apple Cinnamon Baked Oatmeal: Add 1½ cups of diced fresh apples (peeled) to the oats before pouring the custard. The apples soften during baking and add fruity sweetness.
Blueberry Baked Oatmeal: Gently fold 1 cup of fresh or frozen blueberries into the oat mixture before baking. The blueberries burst and create jammy pockets.
Banana Walnut Baked Oatmeal: Mash 2 ripe bananas and stir into the custard. Fold in ½ cup of chopped walnuts. Top with banana slices before baking.
Peach Baked Oatmeal: Add 1½ cups of diced fresh or frozen peaches (thawed and drained) to the oat mixture. The peaches add sweetness and a summery flavor.
Pumpkin Baked Oatmeal: Add ½ cup of pumpkin puree, ½ teaspoon of pumpkin pie spice, and reduce the milk to 1½ cups. The pumpkin adds moisture and fall flavor.
Chocolate Chip Baked Oatmeal: Fold in ½ cup of semi-sweet chocolate chips. Sprinkle a few extra chips on top before baking. The chocolate melts into gooey pockets.
Peanut Butter Banana Baked Oatmeal: Swirl ⅓ cup of creamy peanut butter into the custard. Add 2 mashed bananas. The peanut butter adds richness and protein.
Serving Suggestions
This baked oatmeal is delicious on its own, but it truly shines with toppings:
Warm Toppings:
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Splash of milk, cream, or non-dairy milk
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Drizzle of maple syrup or honey
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Pat of butter
Fruit Toppings:
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Fresh berries (strawberries, blueberries, raspberries)
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Sliced bananas
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Diced apples or pears
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Dried cranberries or raisins
Crunchy Toppings:
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Chopped walnuts, pecans, or almonds
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Toasted coconut flakes
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Granola
Indulgent Toppings:
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Dollop of yogurt (Greek or regular)
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Spoonful of peanut butter or almond butter
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Sprinkle of chocolate chips
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Dollop of whipped cream
Storage & Reheating
Store leftovers in an airtight container in the refrigerator for up to 5 days.
To reheat, place individual portions in the microwave for 30-60 seconds, adding a splash of milk to restore creaminess. You can also reheat the entire casserole in a 350°F oven for 10-15 minutes, covered with foil.
This baked oatmeal freezes well for up to 3 months. Cut into squares, wrap individually in plastic wrap, and place in a freezer bag. Thaw overnight in the refrigerator or reheat directly from frozen in the microwave (add 30-60 seconds).
Why This Recipe Works
This Amish Baked Oatmeal Casserole is a classic for good reason. The combination of old-fashioned rolled oats, milk, eggs, brown sugar, cinnamon, and salt creates a breakfast that is hearty, wholesome, and satisfying. The oats provide fiber and texture. The milk and eggs create a custard that sets as it bakes, resulting in a tender, creamy interior. The brown sugar adds a deep, caramel-like sweetness. The cinnamon provides warmth and spice.
Baking the oatmeal instead of cooking it on the stovetop transforms it into a dish that is more substantial and sliceable. The oats absorb the custard and bake into a tender, cohesive casserole that can be cut into squares or scooped into bowls.
This recipe is proof that you do not need a long list of ingredients or complicated techniques to make a delicious, wholesome breakfast. With six simple ingredients and a hot oven, you can create baked oatmeal that is perfect for busy mornings, holiday breakfasts, or any time you need a warm, satisfying start to the day.