High-Protein Peanut Butter Overnight Oats

There was a morning last spring when I woke up starving but running late, and I remembered the jar I'd mixed the night before while cleaning up dinner. I grabbed it from the fridge, added a handful of berries, and ate it cold in the car. The creamy peanut butter had turned the oats into something almost dessert-like, and the protein kept me full until lunch. I've been hooked ever since.

I started making these for my partner when they complained that cereal left them hungry by mid-morning. The first few times I overdid the milk and ended up with soup, but once I nailed the ratio, it became our weekday ritual. Now we keep a row of jars in the fridge, each one topped differently depending on what fruit we have around.

Ingredients

• Old-fashioned rolled oats: They soften perfectly overnight without turning mushy, and they hold onto all that creamy peanut butter mixture.
• Unsweetened milk of choice: Soy or pea milk adds extra protein, but any milk works as long as you like the taste.
• Plain Greek yogurt: This is what makes the texture thick and rich, plus it boosts the protein significantly.
• Natural peanut butter: The kind that separates a bit works best because it blends smoother, and the flavor is deeper than the sweetened stuff.
• Vanilla or unflavored protein powder: A scoop turns this from a snack into a real meal, just whisk it in well so it doesn't clump.
• Honey or maple syrup: Optional, but a little sweetness balances the richness if your protein powder isn't flavored.
• Pure vanilla extract: Just half a teaspoon makes everything smell like a bakery when you open the jar.
• Fine sea salt: A pinch wakes up the peanut butter and keeps the sweetness from feeling flat.
• Chia seeds or ground flaxseed: They thicken the oats and add a little extra staying power if you need it.
• Ground cinnamon: Warm and cozy, especially good in colder months.
• Fresh fruit, nuts, or chocolate chips: Whatever makes you excited to eat breakfast, really.

Instructions

Prep your jar:

Choose a jar with a lid that seals well, around 12 to 14 ounces. You want enough room to stir without making a mess.

Combine the dry ingredients:

Add oats, chia seeds, flaxseed, cinnamon, protein powder, and a pinch of salt to the jar. Give it a quick shake or stir so the protein powder doesn't clump later.

Whisk the wet mixture:

In a separate bowl, whisk together milk, yogurt, peanut butter, vanilla, and sweetener if using until completely smooth. If it looks too thick, add a tablespoon or two of water or extra milk.

Combine wet and dry:

Pour the peanut butter mixture over the oats and stir really well, scraping the bottom to make sure no dry pockets hide underneath. If it seems stiff, splash in a bit more milk.

Add mix-ins:

Stir in chocolate chips or sturdy fruit like diced apple or banana now. Save delicate berries for the morning so they stay fresh.

Seal and chill:

Put the lid on tight and refrigerate for at least four hours, but overnight is better. The oats will soak up the liquid and turn soft and creamy.

Stir and adjust:

In the morning, give it a good stir and check the thickness. Add a splash of milk if you want it looser.

Top and enjoy:

Spoon on peanut butter, fresh fruit, yogurt, nuts, seeds, honey, or a pinch of flaky salt. Eat it cold right from the jar or scoop it into a bowl.

Save

One weekend I made a triple batch and lined up three jars with different toppings: one with strawberries and almonds, one with banana and chocolate chips, one with blueberries and a drizzle of honey. My friend came over for coffee, saw them in the fridge, and asked if I was meal-prepping for a fitness competition. I laughed and said no, I just really like not thinking before breakfast.

How to Customize for Your Goals

If you want even more protein, use a full scoop of powder, switch to high-protein milk like soy or pea, and pile on the Greek yogurt. For a lower-carb version, swap half the oats for extra chia seeds or hemp hearts, though the texture will be denser. If you're going vegan, just use plant-based milk, yogurt, and protein, and swap honey for maple syrup. I've done all of these and they all work, you just have to know what you're aiming for.

Texture Tricks

The difference between creamy and gluey comes down to the milk-to-oat ratio and how long you let it sit. If you like it thick and spoonable, use the lower end of the milk measurement and add chia seeds. If you want it more pourable, stir in extra milk in the morning. I usually make mine on the thicker side because I eat it with a spoon straight from the jar while I'm getting dressed.

Make-Ahead and Storage

These keep in the fridge for up to two days, but the texture is best within the first 24 hours. If you're prepping multiple jars, leave the toppings off until you're ready to eat so the fruit stays fresh and the nuts stay crunchy. I usually prep two at a time, one for the next morning and one for the day after.

• Store sealed jars toward the back of the fridge where it's coldest.
• Stir well before eating because the oats settle and the liquid rises.
• Add fresh fruit and crunchy toppings right before serving for the best contrast.

Save

Now I keep a jar in the fridge almost every night, and it's become one of those small things that makes mornings feel less chaotic. There's something satisfying about opening the fridge and knowing breakfast is already waiting, thick and sweet and ready to go.

Recipe FAQs

→ How long do these oats keep in the refrigerator?

These overnight oats stay fresh for up to 2 days when refrigerated in a sealed container. For best texture and flavor, add delicate fresh fruits like bananas or berries just before serving rather than storing them mixed in.

→ Can I make this without protein powder?

Absolutely. If you prefer to skip protein powder, increase the Greek yogurt to ½ cup and use high-protein milk like soy or pea milk. You can also add an extra tablespoon of peanut butter or include chia seeds for additional protein and thickness.

→ What's the best milk to use for maximum protein?

Soy milk and pea milk typically offer the highest protein content among plant-based options, usually providing 7–10 grams per cup. Cow's milk naturally contains about 8 grams per cup. Combining your milk choice with Greek yogurt and protein powder creates a substantial protein boost.

→ How can I make this vegan?

Use plant-based yogurt and milk, swap the protein powder for a vegan blend (pea, rice, or hemp-based), and choose maple syrup instead of honey. The taste and texture remain virtually identical, and you still achieve a high-protein breakfast.

→ Why is my mixture too thick or too thin?

Oat absorption varies by brand and type. If the mixture is too thick after soaking, stir in another tablespoon of milk before serving. For a thicker consistency next time, reduce the milk by 1–2 tablespoons or add chia seeds, which gel and create a pudding-like texture.

→ Can I use quick oats instead of old-fashioned rolled oats?

Quick oats work but will yield a softer, more porridge-like texture rather than the chewy, substantial bite of rolled oats. Steel-cut oats are not recommended as they remain too firm even after overnight soaking.