10 Minute Microwave Peanut Brittle – A Microwave Peanut Brittle with Karo Syrup Recipe

10 Minute Easy Microwave Peanut Brittle recipe is the best because it’s quick, easy, crunchy and delicious.  This Peanut Brittle recipe has Karo syrup and baking soda. Add this to your Christmas treats for an old fashioned tradition.

Every Christmas, our lovely neighbor Susan brought a tasty array of treats from her kitchen. To this day, these treats are on my top five all time favorite Christmas Candy list.  It wasn’t really Christmas until Susan dropped off her goodies including this homemade peanut brittle.  Check out the other two recipes below.

Cinnamon Glazed Nuts

Old Fashioned Peanut Butter Balls 

Microwave Peanut Brittle with Karo Syrup Recipe

This easy peanut brittle takes less than 10 minutes from start to finish. The trick to this shortcut recipe is using your microwave. Susan says to use your microwave on high for this recipe.

Another suggestion from Susan is to use a 1 1/2 quart casserole dish to cook the brittle in the microwave. I have also used a large Pyrex bowl myself. Just be sure that your dish is microwave safe.

There are many different brittle recipes out there. This old fashioned peanut brittle uses both baking soda (not to be confused with baking powder) and light corn syrup (also known as Karo).

Ingredient List for Microwave Peanut Brittle with Karo Syrup

• Granulated Sugar
• White Corn Syrup (Karo Syrup)
• Peanuts, roasted and salted
• Butter
• Vanilla Extract
• Baking Soda

How to Make Peanut Brittle in the Microwave

Step by Step Instructions

1. In a 1 1/2 quart casserole dish or a large microwave-safe bowl, mix together granulated sugar and white corn syrup (Karo).
2. Microwave on high heat for 4 minutes.
3. Remove from microwave, and stir in peanuts into the mixture.
4. Microwave for 3 more minutes. Check it at the 2 minute mark to make sure it isn’t burning (if so, do not cook the additional minute).
5. Stir in vanilla extract and butter until butter is fully melted with a silicone spatula.
6. Cook for 1 additional minute.
7. Stir in baking soda until light and foamy.
8. Pour onto a lightly greased sheet pan or pizza pan, spreading it lightly and quickly.
9. Let harden and cool. Color should be golden brown.
10. Break into pieces.

Storage Instructions

Let the leftovers cool completely to room temperature. Store in an airtight container on the counter for up to 2 weeks.

For the full ingredient amounts and recipe steps for easy microwave peanut brittle, scroll to the recipe card at the bottom of this post.

Recipe Variations

• Use Spanish peanuts, chopped almonds, or cashews instead of roasted peanuts.

Recipe FAQs

• Use roasted, salted peanuts. If you prefer small bits of peanuts, chop them up before adding to the brittle.
• The key to this recipe is to work quickly because the microwave peanut brittle hardens really fast.
• Be sure to have a towel or pot holder handy for moving the bowl around. It is hot hot hot, and you don’t want to get burnt.
• Boiling sugar is super hot as well. Resist the urge to touch the peanut brittle with your hands until it has hardened and cooled. Keep little hands away too.
• Spray all surfaces with nonstick cooking spray to help with clean up. This includes the microwave-safe bowl, spatula, liquid measuring cup (for Karo), and the sheet pan.
• Check out our Amazon store for our favorite pantry essentials and kitchen items.

Homemade Christmas Gift Ideas

What are some DYI Christmas gifts on a budget?

Using your kitchen is a great way to whip together some amazing Christmas gifts straight from the heart.  To take a homemade treat to the next level, package the goodies in something special like a new mug or wrap it up in a new kitchen towel, or consider attaching a new serving spoon.

Here’s 15 DIY Christmas gifts straight from our kitchen to yours. We even put together a post all about our favorite homemade holiday gifts!

1. Homemade Hot Cocoa Recipe 
2. Friendship Tea 
3. Homemade Martini Olives
4. Old Fashioned Hot Fudge Sauce
5. Strawberry Freezer Jam
6. White Chocolate Candy Mix 
7. Grandma’s Caramel Corn
8. Candied Peanuts 
9. Red Hot Cinnamon Apples
10. Cinnamon Glazed Nuts
11. Hot Buttered Rum Mix
12. Old Fashioned Peanut Butter Balls 
13. Crock Pot Chili Nuts
14. Pulled Pork Spice Rub 
15. Mom’s Poppy Seed Bread

How long can you store homemade peanut brittle?

When stored properly in an airtight container, homemade peanut brittle can be stored for up to 2 weeks. Be sure to let it cool completely before transferring to the storage container.