Leftover Mashed Potato Cakes

Name: Leftover Mashed Potato Cakes
Prep time: 5 min
Cook time: 15 min
Total time: 20 min
Ingredients: 3 cups mashed potatoes; 2 large eggs; 1 cup shredded cheddar cheese (can also use Gruyère or another favorite cheese); 1/2 cup all-purpose flour (plus more if your mashed potatoes are on the runnier side); 1/4 cup chives, finely sliced (can sub green onions), plus more for garnish; 1/4 cup vegetable oil; Salt and pepper (if your leftover mashed potatoes weren’t already seasoned); Sour cream or Greek yogurt, for garnish (optional)

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These leftover mashed potato cakes are the perfect way to mix up your mashed potatoes for a golden brown, crispy, cheesy side dish.

Mashed potato cakes topped with sour cream and chives on a white plate.

Call me crazy, but sometimes I have a really hard time eating leftovers. I mean, how many days in a row can you eat the same thing!? *boringgggg* But to avoid making every meal from scratch, I’ve had to figure out a way to keep my leftovers from going to waste — I call it *cue jazz hands* Leftover Remix.

These mashed potato cakes were originally a brainchild of mine one New Year’s morning when I wanted to do something about the mountains of leftover mashed potatoes I had hanging out in my fridge. Since then, I’ve experimented a bunch, and the recipe I use today is a bit of a mash-up (pun intended 😂) of the different recipes I’ve tried over the years.

About leftover mashed potato cakes

These aren’t just any old potato pancakes — they’re crispy on the outside, creamy on the inside, and loaded with sharp cheddar cheese and fresh herbs.

Whether you’re staring at a mountain of leftover spuds from Thanksgiving dinner or just want to reimagine your mashed potatoes from last night, this leftover mashed potato recipe is going to be your new favorite side dish.

These potato cakes use simple ingredients and take only a few minutes to prep. The best part? You probably already have all the ingredients in your kitchen.

My favorite thing about them (besides remaking your leftovers into a completely new dish) is that they work for breakfast, lunch, or dinner. They’re the perfect side dish for pork chops, a cozy lunch with a dollop of sour cream, or serve them up for breakfast, topped with a fried egg. You could even top them with crème fraiche and caviar for an extra special occasion (and omggg how amazing would that be! Note to self — must try this!).

Baked honey mustard salmon on a white plate with roasted broccoli and a mashed potato cake.

Ingredients

3 cups mashed potatoes (at room temperature works best)
2 large eggs
1 cup shredded cheddar cheese (or Gruyère, Parmesan cheese, or your favorite way to cheese it up)
½ cup all-purpose flour
¼ cup vegetable oil (or use avocado oil, canola oil, or olive oil)
¼ cup chives, finely sliced (sub with green onions if you’d like)
Salt and black pepper, to taste
Sour cream or Greek yogurt, for garnish
Optional Add-Ins: Try adding a pinch of garlic powder, onion powder, or a handful of crispy bacon bits for texture (yum!)

How to make leftover mashed potato cakes

This is an overview of how to make mashed potato cakes. See the recipe card below for detailed ingredients and instructions.

Make the Potato Mixture

In a large bowl, stir together the leftover mashed potatoes, flour, eggs, cheese, and chives (or green onions). Mix until you get a stiff batter that holds its shape when scooped (if it’s like cookie dough, it’s the right consistency). If it feels too soft or sticky, add a tablespoon of flour at a time until it firms up.

💡 Pro Tip: Not sure how much flour to use? It depends on how creamy your leftover potatoes are. For runnier mashed potatoes (with a lot of cream or butter), add more flour to help bind them.

Heat the Oil

Heat the vegetable oil in a large nonstick skillet or frying pan over medium-high heat. You’ll know it’s ready when the oil shimmers.

💡 Pro Tip: Want to lighten things up? Use an air fryer! Scoop the leftover mashed potato patties onto a sheet of parchment paper and air fry at 375°F for about 10–12 minutes, flipping halfway for best results.

Shape and Cook the Cakes

Scoop out about ⅓ cup of the potato cake mixture (a measuring cup works great here) and drop it into the skillet. Gently flatten the cakes with the back of a spoon or cup so they cook evenly in a single layer. Allow space between — you may have to cook in batches.

Cook for 3-5 minutes on one side until golden brown and crispy, then flip and cook the other side for 2-3 more minutes.

💡 Pro Tip: These things splatter! Use a splatter guard if you have one, and keep kids and white shirts far, far away.

Drain and Serve

Transfer each cake to a paper towel or a wire rack on a baking sheet to drain excess oil. This keeps them crispy and avoids the dreaded soggy cake.

Top with some sour cream or Greek yogurt, sprinkle with more chives or green onions, and any fresh herbs you like. Serve immediately, or keep warm in the oven (just heat it to 200ºF) on a sheet pan if you're making a big batch.

Frequently asked questions

Can I prep these ahead of time?

Yes! Prep the mashed potato mixture and store it in an airtight container in the fridge for up to 2 days. You can also pre-cook the cakes and reheat them in the oven at 375°F until crispy.

What if my mixture is too wet or too dry?

If it’s too wet, add more purpose flour or even a tablespoon of bread crumbs. If it’s too dry, add an extra large egg or a splash of milk to loosen it up.

What goes best with mashed potato cakes?

These mashed potato cakes are so versatile. Try them with fried eggs and bacon for a breakfast hash-style meal, with honey mustard salmon or grilled chicken as a dinner side dish, as an appetizer with a creamy dipping sauce (think chipotle mayo or garlic aioli), or with leftover turkey and a spoonful of leftover cranberry sauce for a mini post-Thanksgiving feast.

How can you store mashed potato cakes?

Prepped mashed potato cakes (not cooked) can be stored in an airtight container in the refrigerator for up to 2 days. Alternatively, you can pre-cook the cakes, store them in the fridge for 3-4 days, and reheat them in the oven on a parchment paper-lined sheet pan at 375°F until crispy.

Do mashed potato cakes freeze well?

Yes! After frying and drying, freeze the extras in a freezer-friendly bag with parchment between layers. Reheat in the oven or air fryer straight from frozen.

What’s the best way to reheat potato cakes?

The best way to reheat mashed potato cakes is in the air fryer or on a baking sheet lined with parchment paper in the oven. This brings back that golden brown crisp without drying them out.

Variations + substitutions

This easy recipe is super adaptable.

🔁 Swap in leftover mashed sweet potatoes for a slightly sweet, earthy variation. Add cinnamon and a pinch of chili powder!
🔁 Swap the cheddar cheese for Gruyere, mozzarella, or crumbled feta.
🔁 If you don’t want to use vegetable oil, try using avocado oil, canola oil, or olive oil instead.
🔁 Fresh out of chives? Sub in finely sliced green onions.
➡️ Mix in sautéed yellow onions or garlic for extra flavor.
➡️ Add a pinch of garlic powder, onion powder, or a handful of crispy bacon bits for texture.
➡️ Top with poached eggs and hollandaise sauce for a twist on Eggs Benedict.

Special diets

If you have a special diet you're adhering to, here are some ways you can adjust this recipe.

Gluten free: Use a 1:1 gluten-free flour in place of the all-purpose flour.
Dairy free: Use a dairy-free cheese, or omit it altogether.
Whole30 / Paleo: You can try using almond flour and leaving out the cheese, but admittedly, I haven’t tried this.
Keto: These are potatoes, so they’re not going to work here. Sorry!

Related recipes

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Before you go...

⭐️ If you make these leftover mashed potato cakes and love them, please leave a comment and leave a five-star rating for this recipe! ⭐️

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