Name: Microwave Peanut Brittle
Cook time: 8 min
Total time: 38 min
Ingredients: 1 cup granulated sugar; ½ cup light corn syrup ((I used Karo brand clear/light syrup)); ½ teaspoon salt; 1 cup raw peanuts, (blanched); 2 tablespoon unsalted butter; 1 teaspoon vanilla extract; 1 teaspoon baking soda

If you’re picturing pretty tins of homemade candy lined up for everyone on your Christmas list, this is the microwave peanut brittle to fill them with. It gives you thin, crisp pieces without a candy thermometer or the stovetop guesswork that may have ruined your last batch.

A black plate with pieces of Microwave Peanut Brittle sits on a dark wooden table. A bowl of shelled peanuts and more brittle pieces are nearby on a slate board.

One batch spreads out to roughly 8×10 inches and keeps for a month in a sealed container, so you can start well before you need to hand any of it over.

Ingredient Notes

Assorted baking ingredients on a counter, perfect for making Microwave Peanut Brittle, including blanched peanuts, sugar, corn syrup, baking soda, butter, vanilla extract, and a box of baking soda, in front of a white tiled wall.

There Is No Substitute For Corn Syrup

Corn syrup is the one ingredient here with no way around it. It stops the sugar turning grainy while it cooks, and it is why brittle sets glassy rather than sandy.

Honey and maple syrup both get suggested. Neither one gives the same snap.

Buy light corn syrup. The bottle will say light or clear on the front, and the dark kind will change both the color and the flavor.

Buy Raw Peanuts, Not Roasted

Buy raw, shelled peanuts for this recipe. Do not buy roasted peanuts. The raw peanuts roast in the bowl while the sugar cooks, so both are ready at the same time. Roasted peanuts can burn before the sugar reaches the brittle stage.

Blanched does not mean roasted. It only means the papery skins have been removed. Raw blanched peanuts are the most convenient, but regular raw peanuts work just as well.

If you can only find raw peanuts with the skins still on, you can still use them. Wrap them in a clean dish towel, rub them together to loosen the skins and then pick out the peanuts. Your finished brittle will be no different from a batch made with raw blanched peanuts.

Changing The Nuts

You do not need a second recipe to give your brittle-making some variety. Replace the peanuts with the same amount of raw, unsalted cashews, pecans, walnuts, almonds or pistachios. Starting with raw nuts allows them to toast as the sugar cooks instead of scorching before the brittle is ready.

You can also divide the measured amount between two nuts. Half peanuts and half cashews gives you a different batch without changing anything else in the recipe.

Adding A Flavor Boost

For a spiced brittle, add a pinch of cayenne or chipotle with the salt. For a salted top, scatter a small amount of flaky salt over the brittle before it sets. The recipe already contains salt, so use a light hand.

For something closer to a candy bar, my toffee brittle finishes the same kind of peanut candy with a layer of melted chocolate over the top.

Every Microwave Is Different

The 8 minutes on the recipe card is what my microwave needed. Yours may want six, and it may want 10.

This is the single most common thing that goes wrong with microwave brittle. Wattage varies from about 700 to over 1,600, and cooks working from the same instructions end up with one batch burnt and the next chewy.

A glass measuring cup filled with white beans soaking in water on a white marble surface, reminiscent of preparing ingredients for recipes like Microwave Peanut Brittle. — Before it goes into the microwave.

A glass mixing bowl filled with lumpy banana bread batter sits on a white marble countertop, next to a plate of homemade Microwave Peanut Brittle. — After it immediately comes out.

Go by color instead of time in the microwave. Anything past caramel toward brown has gone too far.

If you would rather cook to a number than to a color, my old fashioned peanut brittle uses a candy thermometer on the stovetop and gets you to the same place.

Making Several Batches

Make separate batches rather than doubling the recipe. A larger amount heats differently, can boil over and will not be ready in the same amount of time.

A thick, nut-filled batter for Microwave Peanut Brittle is being poured from a glass bowl onto a foil-lined baking sheet. — After you pour the brittle, let the hot bowl cool before adding water. Putting water into very hot glass can crack it.

If you are making several batches, rotate between two microwave-safe bowls. While one cools and soaks, the other can go into the microwave. Measure each batch of ingredients ahead of time and prepare all the baking sheets before you begin.

Close-up of pieces of Microwave Peanut Brittle on a textured metal baking sheet, showing golden caramelized sugar and embedded peanuts.

The first batch will confirm the correct cooking time for your microwave. Write it down, then use that time as the starting point for every batch that follows.

Once you have your number, the same afternoon is enough to get through several of my other Christmas candy recipes as well.

Pick A Dry Day

You can cook the sugar perfectly and still end up with sticky brittle if there is too much moisture in the air. It may feel crisp when you break it, then soften by the next day.

Cooked sugar absorbs moisture, so check the forecast before making several batches and choose the driest day you can.

Once the brittle is completely cool, move it straight into an airtight container. Do not leave it sitting uncovered on the counter, especially in damp weather.

Recipe Testing Notes

This post went live in October 2019. It was tested by professional recipe tester, Teresia, in May 2026 and she raved about its accessibility.

“I have always found peanut brittle an intimidating recipe, probably due to the nature of molten sugar. This recipe was very user friendly and not daunting at all.”

Teresia S., Recipe Tester

Close-up of pieces of Microwave Peanut Brittle on parchment paper, showing glossy, golden-brown candy with whole peanuts inside. A bowl of peanuts is partially visible in the upper left corner of the image.

This homemade peanut brittle candy will be a yummy addition to your treats this holiday season, along with:

Christmas fudge covers the soft end and keeps about as long as the brittle does, so both can be made in the same week and packed on the same day.
Peppermint bark gives you a second snap with a completely different flavor, and it breaks into shards the same way, so the two sit well next to each other.
Christmas Chex mix fills in around the pieces, which keeps the brittle from moving around loose in the tin.

Food Round Ups

45+ Budget-Friendly Edible Gift Ideas (Quick & Easy)

Microwave Peanut Brittle

5 from 2 votes

This classic sweet and salty microwave peanut brittle is a favorite to make during the holidays.

Cook Time 8

Total Time 38

Servings

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Ingredients

1 cup granulated sugar
½ cup light corn syrup (I used Karo brand clear/light syrup)
½ teaspoon salt
1 cup raw peanuts, blanched
2 tablespoon unsalted butter
1 teaspoon vanilla extract
1 teaspoon baking soda

Instructions

Prepare a rimmed baking sheet by lining it with a piece of aluminum foil and generously buttering the aluminum foil all over. Alternatively, you can line the baking sheet with a silicone baking mat. Set aside.
In a 2-quart, microwave-safe bowl, place the sugar, light corn syrup, salt, and peanuts. Stir to combine, then microwave on high for 4 minutes.
Very carefully remove the mixing bowl and give the corn syrup mixture a quick stir before microwaving for another 4 minutes. Carefully remove the hot bowl and place it on a heat-safe counter.
Add the unsalted butter and vanilla extract. Stir quickly to combine, then add the baking soda. Give the microwave peanut brittle a good stir to combine all the ingredients. Quickly, and carefully, pour the mixture onto the prepared rimmed baking tray.
Using a rubber spatula, spread the peanut brittle into an even layer in a rough 8×10-size rectangle on the prepared baking sheet.
Allow the microwave peanut brittle to cool on the counter for a minimum of 30 minutes, up to an hour, before breaking it into smaller pieces.

Notes

Note that if you use medium or dark corn syrup (Karo syrup), that your peanut brittle will become very dark and will not turn out like this recipe. It will not only be a very dark color but will also be a much richer flavor than traditional peanut brittle.
CAUTION! You are working with very hot sugar and a very hot bowl. Make sure that you use caution in handling both the brittle and the mixing bowl. I highly suggest that you use a 2-quart (8-cup) microwave-safe glass measuring bowl that has a handle. It will be much easier to transfer the hot bowl in and out of the microwave. It will also make it much easier to handle while stirring the cooked sugars.
This recipe was made using a 1000-watt microwave.
You will notice that the mixture of corn syrup and sugars, along with the peanuts, will darken to a beautiful caramel color when done heating in the microwave. This is perfect!
I highly suggest using a rubber spatula to mix the sugars and peanuts for this recipe. It also works best for spreading the hot brittle mixture onto the prepared pan.
DO NOT place the hot bowl into a cold sink or into (or under) water until the bowl is completely cool. Allow the bowl to cool on the counter before trying to clean it. You will risk the glass bowl shattering if the proper care is not taken.