This Peanut Butter Baked Oatmeal turns simple oats into a cozy, hearty breakfast the whole family loves. It’s warm, satisfying, and tastes a little like a peanut butter cookie and oatmeal had a baby – in the best possible way. Some people call it Amish Breakfast Casserole, which somehow makes me love it even more.
If you enjoy baked oatmeal, you’ll also want to try my Breakfast Casserole or Homemade Cake Donuts!
Why You’ll Love This Peanut Butter Baked Oatmeal
It’s truly a one-bowl wonder. Just mix everything together, pour it into a baking dish, and let the oven do the rest. The peanut butter makes it extra rich and comforting, but it’s also very flexible – you can easily leave it out or swap it for almond butter if needed.
The edges get beautifully golden while the center stays soft and gooey. And yes… that crack on top is completely normal and actually a good sign!
FAQs
Can I make this without peanut butter? Yes! Simply omit the peanut butter. The baked oatmeal will still be delicious. Feel free to add raisins, dried cranberries, or fresh berries for extra flavor.
Can I use old-fashioned rolled oats instead of quick oats? You can, but the texture will be a bit heartier and chewier. Quick oats give a softer, more cohesive result. If using rolled oats, add an extra 2-3 tablespoons of milk.
What’s the best pan to use? An 8×8-inch glass dish gives the softest, gooey texture. A metal pan works too but may brown the edges a little faster.
Can I make this gluten-free? Yes! Just use certified gluten-free oats and double-check that your baking powder is gluten-free.
Is this recipe very sweet? It has a pleasant sweetness similar to a peanut butter cookie. You can reduce the brown or granulated sugar by 1-2 tablespoons if you prefer it less sweet.
How to Make Ahead
This baked oatmeal is perfect for meal prep!
Full make-ahead: Bake the oatmeal, cool completely, cover, and refrigerate for up to 4 days.
Night before: Assemble the mixture, pour it into the baking dish, cover tightly, and refrigerate overnight. In the morning, let it sit on the counter while the oven preheats, then bake as directed (it may need 3-5 extra minutes).
How to Serve Baked Oatmeal
As you can see by the first picture in the blog post, we like a little organic maple syrup drizzled on top. Other fun variations are:
- fresh fruit such as banana or strawberry
- adding homemade whipped topping with raisins (my boys favorite)
- fresh vanilla yogurt
And, of course, we love it warm. Quite honestly, this dish has never made it to the “leftover” stage in our house, so I don’t even know if it reheats well! My gut says that yes, it would. Just pop it in the microwave and enjoy. 🙂
How to Store
Refrigerator: Store leftover baked oatmeal covered in the refrigerator for up to 4 days.
Freezer: Cut into portions, wrap tightly, and freeze for up to 2 months. Thaw overnight in the refrigerator.
Reheating: Warm individual portions in the microwave with a splash of milk for 30-60 seconds. For larger amounts, reheat in a 325°F oven until warmed through.
Baked Oatmeal
Ingredients
- 1 ½ cups quick cooking oats
- ¼ cup packed brown sugar
- ¼ cup granulated sugar
- ¾ cup milk
- ¼ cup melted butter
- ½ cup peanut butter (creamy or chunky works)
- 1 teaspoon vanilla
- 1 large egg
- 1 teaspoon baking powder
- ¾ teaspoon kosher salt (if using table salt use ½ teaspoon)
Instructions
- Preheat oven to 350°F. Put all the ingredients in a bowl and mix until combined. It will appear very wet.
- Pour mixture into baking dish. I used an 8×8 glass baking dish because I wanted a soft and gooey texture. (If you use a 9×13 pan they will be a little thinner and less gooey, but also more familiar and delicious.)
- Bake for 20-25 minutes or until the edges are golden brown. If it cracks on top don't worry, it's not overdone. An inserted toothpick should be removed with crumbs clinging to it.
- Serve warm.
Notes
Night before: Assemble the mixture, pour it into the baking dish, cover tightly, and refrigerate overnight. In the morning, let it sit on the counter while the oven preheats, then bake as directed (it may need 3-5 extra minutes).
Full make-ahead: Bake the oatmeal, cool completely, cover, and refrigerate for up to 4 days.
Did you make this recipe?
Thank you for making my recipe! You took pictures, right? Well go ahead and post them on Instagram! Be sure to mention me @iambaker and use the hashtag #YouAreBaker.
Images updated. Originally published in 2011.
I made this yesterday and it tastes great, but it came out a little more crumbly (is that a word?) than I expected. I live at a somewhat higher elevation than most (about 4000 feet) and am a novice baker. Can someone help me adjust this recipe? My thoughts are to reduce the baking powder a little or add an egg, but my preference is to have someone with more experience with such things give me some guidance before I start experimenting.
Thanks in advance!
Dave in Montana
Hayley Fraire
Say, you got a nice blog post.Really looking forward to read more. Will read on…
This recipe is fantastic!!!!
It is easy to make up on Sunday evening and then eat it throughout the week. Actually, I would MUCH rather have this now instead of “regular oatmeal”. My 14 and 16 year old boys have been eating this when I am out of cereal! I use either Truvia or splenda instead of regular sugar. Thanks for this awesome recipe! It is a huge hit at my house!
I made this just now, and while my bestie and my kids LOVE it, it’s a bit too peanut buttery for me, personally. I think next time, I will add Nutella, or some other non peanut spread. I mean, I ATE it, of course, and it was yumma licious. An I will put it in the 8×8 pan. I think I will like the gooeyer version. Can’t wait to try it again.
I made this last night for dinner because I was in the mood for breakfast. Everyone loved it… even the 2 year old who never eats anything. I couldn’t wait to make it for Breakfast again this morning. 🙂
I make Baked Oatmeal all the time in 20 oz. Corelle baking mugs. I put some in the fridge and some in the freezer (after baking). I usually just take them out of the fridge and microwave them for 30 seconds to a minute and then into a 375° oven for a few minutes till slightly more browned. let cool for a few minutes on a cooling rack till I can pick the mugs up by hand without a potholder. Then enjoy.
Great recipes!
Could I swap out the peanut butter for cookie butter?
This is my second time making it and I absolutely love it!!! It’s for two people plus a bit of leftovers…
I found that this recipe just falls apart every time I made it. So I contacted a chef-friend of mine and he said to add 1 Tbsp of oil. That helped !