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Twice baked mashed potatoes (also known as twice-baked mash or potato casserole) are the ultimate crowd-pleasing side dish. Creamy, fluffy mash is made with roasted potatoes for the best flavour and texture (roasting means less water content), then it’s mixed with garlic butter and finished with a golden, cheesy, crispy top, and then baked again. Yes, it is as delicious as you imagine it to be.
This guide will walk you through the full recipe, plus tips for make-ahead prep, freezing, troubleshooting, and some other delicious variations. By the end, you’ll have perfect twice baked mashed potatoes every time.
Table of Contents
Why you will love this recipe:
- Fuss-free: Roast the potatoes whole so you don’t need to peel. Minimal hands-on time.
- Make-ahead friendly: Assemble ahead and bake when needed.
- Comfort food at its finest with garlic-parsley butter, and crispy cheese topping.
- Ridged, cheese-topped surface crisps perfectly in the oven, creating a contrast of textures.
Ingredients:
Full recipe can be found in the printable recipe card at the bottom of the post, just scroll down!
Maris Piper potatoes: I find these best and widely available in the UK. They have a fluffy, dry texture. King Edward potatoes work well, too. If you are in the US or elsewhere, a Russet potato is a good swap.
Egg yolk – adding an egg yolk to mashed potatoes makes them creamier, richer and just better, but you can skip it if you prefer.
Milk – I use whole or semi-skimmed milk.
Substitutions and Variations:
Plain butter: if you don’t want to make garlic butter, you can skip that step and just add plain melted (or softened) salted butter in place.
Vegetarian: Fold in sautéed leeks or crispy cabbage – it’s so good and inspired by Colcannon.
Bacon & chive: Add cooked chopped bacon and spring onions.
Creamy style: Replace part of the milk with crème fraîche or sour cream for tang.
Dairy-free: Use plant butter and unsweetened plant milk such as oat. Skip the egg yolk if needed.
Here’s how to make twice baked mashed potatoes:
Here’s a step by step guide for what you need to do, but you can find the full recipe at the bottom of the page for detailed instructions.
ONE: Preheat the oven to 180°C fan / 200°C / 400°F.Pierce the potatoes all over with a fork and place them on a baking tray. Roast for 1 hour to 1 hour 10 minutes, or until very soft when squeezed.
TWO: Melt the butter in a small saucepan. Add the chopped garlic, swirl for a few seconds, then remove from the heat. Stir in the chopped parsley and set aside.
THREE: Once the potatoes are cooked, remove from the oven and slice in half. Cool for 5 minutes.
FOUR: Hold a half with a clean tea towel, and scoop the flesh into a bowl. Repeat until all the halves are scooped.
FIVE: Pass the potato through a ricer, or mash until completely smooth.
SIX: Add the warm garlic–parsley butter. Pour in the hot milk (start with 100ml and add more if needed). Mix until smooth and creamy, then stir in the egg yolk. Add the cheese and season generously with salt and black pepper.
SEVEN: Spoon the mash into a small baking dish (approx. 20cm diameter). Smooth the top, then create ridges with a fork. Scatter over a layer of grated cheese.
EIGHT: Bake for 20 minutes, or until golden and crisp.
Cooking Tips:
Ricer vs masher: using a ricer makes fluffier, smoother mash but I know not everyone has one. A masher works well too.
Ridging & topping: Make proper ridges with a fork and sprinkle cheese, as these craggly edges make for good texture and crispness. If needed, finish under grill for 1–2 minutes for extra browning.
Frequently Asked Questions
Bake at 180°C fan / 200°C for 3–5 extra minutes than listed – so roughly 22 to 28 minutes. Use your common sense too and test if you aren’t sure. Dip a butter knife into the mash and then touch the knife gently on the back of your hand. If it’s hot, you know it’s ready to serve. If not, pop back in the oven for a few minutes.
Yes you can freeze twice baked mashed potatoes – just freeze before adding the cheese and the second bake. Cool fully, wrap airtight, freeze up to 3 months. Thaw overnight, cover with cheese, then bake 25-35 minutes uncovered.
The fats and natural emulsifiers in the yolk bind the ingredients together, creating a smoother texture and enhancing the flavour. Essentially, adding egg yolks to mashed potatoes makes them creamier, richer and just better, but you can skip it if you prefer.
Other recipes you might enjoy:
To serve alongside creamy twice baked mashed potatoes, you might like to serve red wine braised short ribs, crispy air fryer pork, or garlic butter steak bites. Or my leftover turkey ham pie with garlic butter is a great option too.
Side Dishes
Potato Salad with Dill and Pickles
Smoked Salmon Recipes
Smashed Potatoes with Crème Fraîche & Smoked Salmon
If you tried these Twice Baked Mashed Potatoes or any other recipe on the site, please do leave a rating or comment and let us know how it went!
Twice Baked Mashed Potatoes
Ingredients
- 1 kg Maris Piper potatoes
- 180 g butter
- 3 garlic cloves, finely chopped
- Small bunch of parsley, finely chopped
- 100-150 ml hot milk
- 1 egg yolk
- 75-100 g grated cheddar or Gruyere, plus extra for topping
- Sea salt and black pepper
Instructions
- Preheat the oven to 180°C fan / 200°C / 400°F.
- Pierce the potatoes all over with a fork and place them on a baking tray.
- Roast for 1 hour to 1 hour 10 minutes, or until very soft when squeezed.
- Melt the butter in a small saucepan. Add the chopped garlic, swirl for a few seconds, then remove from the heat. Stir in the chopped parsley and set aside.
- Once the potatoes are cooked, remove from the oven and slice in half. Cool for 5 minutes.
- Hold a half with a clean tea towel, and scoop the flesh into a bowl. Repeat until all the halves are scooped. Pass the potato through a ricer, or mash until completely smooth.
- Add the warm garlic–parsley butter. Pour in the hot milk (start with 100ml and add more if needed). Mix until smooth and creamy, then stir in the egg yolk. Add the cheese and season generously with salt and black pepper.
- Spoon the mash into a small baking dish (approx. 20cm diameter).
- Smooth the top, then create ridges with a fork. Scatter over a layer of grated cheese. Bake for 20 minutes, or until golden and crisp.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
These twice baked mashed potatoes are the perfect dish to get ahead when hosting, as you can make them and pop in the fridge until you are ready to bake. With a garlic parsley butter mixed through, it is so good.