These mashed potato buttermilk biscuits are made with 7 simple ingredients and oven-baked in a greased cast iron skillet for 35 minutes. They are a great way to use up any leftover mashed potatoes. Enjoyed hot and fresh with butter. This recipe yields 12 and makes a great addition to any dinner table.

Heather's Thoughts
As a Southern cook, biscuits are a love language. Cast iron skillet buttermilk biscuits are the ultimate hero but soft sweet potato biscuits, 3 ingredient buttermilk drop biscuits, and flaky and cheddar chive biscuits are big favs too!
Buttermilk biscuits were one of the first things my mom taught me how to cook. She showed the the delicate way to mix and pat out so as not to overwork the dough (because tough dense biscuits are a no-go!) and then we carefully placed them inside cast iron skillets that have been in the family for over 100 years! Of course, they are greased with bacon grease from the mason jar in the fridge because all good Southern gals have a mason jar of bacon grease in their fridge!
We had an abundance of mashed potatoes left over from a dinner I made a couple of months back. Usually, my go-to to use them up is either mashed potato pancakes or feeding them to my son - but I wanted to try something new since I had so much left.
I decided to test them out in biscuits and OH MY GOSH! After several tests to get them just right, I AM OBSESSED! It has the same great taste as your traditional fluffy buttermilk biscuit but it has this hint of mashed potato to it that is just so good! It is soft, fluffy, and tender in all the right ways!
The method for making is the same as your traditional biscuit. Cut cold cubed butter into flour, baking soda, baking powder, and salt. Add in buttermilk and mashed potatoes and gently mix to being together. Cut out with a biscuit cutter (or cookie cutter) on a floured countertop and place in a grated cast iron skillet. These bake in the oven for 35 minutes and the result is a hot and fresh tender biscuit that needs to be slathered in butter, green onion and parm butter, your favorite jams! I know you're going to be obsessed with these!
Equipment Needed
You will need a couple of tools that will making biscuits just a bit easier.
- Pastry Cutter - this will help cut the fat into the dough making it ultra tender and flaky
- Cast Iron Skillet - the key to cooking these biscuits
- Biscuit Cutter or Cookie Cutter - the tool needed for cutting out the biscuits
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How to Make Buttermilk
Fun fact...I never buy buttermilk. On the rare occasion, I need buttermilk for a recipe I usually only need a cup or so and they don't sell it in small enough containers that it would just go bad before I use it - because again I don't use it but for a couple of baking recipes.
BUT! We always have whole milk on hand and we always have white vinegar - so there is no need to buy actual buttermilk from the store. 99% of the time I just make my own buttermilk at home in just 5 minutes (the recipe is in the link!).
Welcome to my kitchen, let's make biscuits!
Did you know that you can freeze biscuits either unbaked or baked? It is so simple and is great to have them on hand for company when they come over for dinner! For Unbaked Biscuits: make and cut out the biscuits. Place on a baking sheet lined with parchment paper and put in the freezer for 30 minutes to flash freeze. Store in a freezer-safe airtight bag or container and freeze for 6 months. To bake, place frozen biscuits in a greased cast iron skillet and bake at 450 for 40-45 minutes (or until just golden brown on top). For Baked Biscuits: Bake and cool biscuits. Place on a baking sheet and place in the freezer for 30 minutes to flash freeze. Put the frozen baked biscuits in a freezer-safe ziptop bag sealed airtight for 6 months. To thaw - move to fridge for 24 hours before use. You can freeze stale biscuits as well to use in Cornbread Stuffing during the holidays.
Uses for Stale Biscuits
Leftover mashed potato biscuits will be stored in an airtight bag for 3 days. But when they are on their last legs and getting a bit hard and stale, don't throw them out! Instead, save them for the following uses:
- Make homemade breadcrumbs: let the biscuits sit out on a baking sheet for 24 hours to harden and stale. Place in a food processor and pulse until fine crumbles with salt, pepper, and whatever herb of choice. Place on a baking sheet and toast at 300 for 10ish minutes until lightly golden brown - stirring halfway through. Store in an airtight container for a month or in the freezer for up to a year and use in any recipe calling for breadcrumbs.
- Use for Baked Southern-Style Cornbread and Biscuit Dressing during the holidays: let the biscuits sit out on a baking sheet for 24 hours to harden and stale. If not the holiday season yet, then place stale biscuits in an airtight ziptop bag in the freezer until the holidays or until needed. Remove and use in a southern cornbread and biscuit dressing recipe that requires stale biscuits and cornbread!
Recipe
Leftover Mashed Potato Buttermilk Biscuits (Tender!)
- Total Time: 55 minutes
- Yield: 12 1x
Description
These mashed potato buttermilk biscuits are made with 7 simple ingredients and oven-baked in a greased cast iron skillet for 35 minutes. They are a great way to use up any leftover mashed potatoes. Enjoyed hot and fresh with butter. This recipe yields 12 and makes a great addition to any dinner table.
Ingredients
- 2 Cups Flour
- 1 Tablespoon Baking Powder
- ¾ Teaspoon Salt
- ¼ Teaspoon Baking Soda
- ¼ Cup Butter- cold and cubed
- 1 Cup Buttermilk
- 1 Cup Leftover Mashed Potatoes
Instructions
- Preheat the oven to 450 degrees Fahrenheit.
- Mix dry ingredients in a large bowl.
- Using a pastry cutter, cut in the butter cubes until the dough has pea-sized clumps in it and is crumbly.
- Add in the buttermilk and mashed potatoes. Gently mix until the dough has just come together. Do not over-mix!
- Place dough on a lightly floured surface and gently bring it together in a ball or round disk.
- With a rolling pin, gently roll out the dough until it is about ½-3/4" inches tall. With a round biscuit or cookie cutter, cut straight down into the dough and lift up. Repeat until all the dough has been used.
- Rub either bacon grease or butter in a cast iron skillet using a paper towel. Place the cut biscuits into a greased cast iron skillet (the biscuits can be close together and touch).
- With the remaining dough, gently bring it together and pat it out into a disk again. Cut out more biscuits and place them in the skillet. Repeat this process until all the dough has been used - being careful not to overwork the dough during this process.
- Place the cast iron skillet in the preheated oven and bake for 35 minutes.
- Remove from the oven and enjoy immediately hot and fresh with butter, green onion and parm butter, your favorite jams.
Notes
- To grease the cast iron skillet, put a little bit of shortening, lard, or butter on a paper towel and spread around the skillet until the bottom and sides are lightly covered.
- Leftovers can be stored in a zip-top bag for 3 days. These make excellent breakfast sandwiches too. Pop in the microwave for 10 seconds to gently warm again.
- Use stale biscuits to make homemade breadcrumbs or Baked Southern-Style Cornbread and Biscuit Dressing.
How to Freeze
- Unbaked Biscuits: make and cut out the biscuits. Place on a baking sheet lined with parchment paper and put in the freezer for 30 minutes to flash freeze. Store in a freezer-safe airtight bag or container and freeze for 6 months. To bake, place frozen biscuits in a greased cast iron skillet and bake at 450 for 17-20 minutes.
- Baked Biscuits: Bake and cool biscuits. Place on a baking sheet and place in the freezer for 30 minutes to flash freeze. Put the frozen baked biscuits in a freezer-safe ziptop bag sealed airtight for 6 months. To thaw - move to fridge for 24 hours before use. You can freeze stale biscuits as well to use in Cornbread Stuffing during the holidays.
- Prep Time: 20 minutes
- Cook Time: 35 minutes
- Category: Bread
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 biscuit
- Calories: 144
- Sugar: 1.4 g
- Sodium: 251.9 mg
- Fat: 5.7 g
- Carbohydrates: 20 g
- Fiber: 1 g
- Protein: 3.2 g
- Cholesterol: 14.9 mg
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