Peanut Butter M&M's

This decadent treat's packed with layers of peanut butter cake and crazy pops of color from M&M's. Each bite is held together with a dreamy peanut butter frosting. If you're wild about peanut butter and chocolate candies, this one's sure to have you grinning from ear to ear.

The first time I fixed this cake was for my nephew's birthday after he went on about loving peanut butter and M&M's. His huge smile when I set it out is still one of my happiest memories. Now, everyone keeps asking me to make one for every get-together.

Dreamy Ingredients

• M&M's: Brings bursts of crunch, color, and a pop of chocolate
• Heavy cream: Gives the frosting a fluffy, easy-to-spread finish
• Powdered sugar: Makes everything silky smooth for the topping
• Buttermilk: Adds a tangy kick and keeps things nice and moist
• Vanilla extract: Rounds out the flavors with a little coziness
• Large eggs: Makes sure the cake doesn’t fall apart and adds moisture
• Granulated sugar: Sweetens things up and keeps the crumb light
• Creamy peanut butter: That classic taste—try Jif or Skippy for the best results
• Unsalted butter: Richness without surprise salt—so you’re in charge
• Salt: Brings out all the peanutty goodness
• Baking powder and baking soda: Double up to give your cake a great rise
• All-purpose flour: Gives you a cake that’s just sturdy enough, not heavy

Simple Instructions

Decorate:

Scatter a handful of extra M&M's on top, then press more candies around the sides for extra flair.

Stack and Finish:

Set your first cake layer on a plate, slather plenty of frosting across the top, pile on the next layer, then cover the top and sides. For a super smooth look, grab a spatula or bench scraper—run it under hot water and dry it first.

Cream Frosting:

Beat the butter with peanut butter until it’s dreamy and smooth (about 3 minutes). Mix in the powdered sugar a bit at a time so you don’t get a sugar storm. Pour in cream and vanilla, then whip it on high for a few minutes until it’s lightly fluffy.

Let Cakes Cool:

Leave the cakes in the pans for 10 minutes. Run a knife gently along the sides and flip them over onto a wire rack. Now, just let them chill until completely cool—even if you’re dying to keep going!

Get Baking:

Pour the batter into your cake pans, leveling out the tops. Bake them for about 25–30 minutes. They’re done when a toothpick comes out clean or just a little bit sticky.

Toss in M&M's:

Gently fold the M&M's into the batter with a spatula. To keep them from sinking, toss them with a tiny dusting of flour first.

Stir Together:

Add your flour mixture to the wet bowl in three separate rounds, switching off with the buttermilk (start and finish with dry stuff). Don’t overmix, just combine each time.

Add Other Wet Stuff:

Crack in one egg at a time, blending each in before adding the next. Mix in that vanilla. Stop mixing as soon as things look combined—otherwise, your cake could end up chewy.

Start with Butter & Sugar:

In a big bowl, whip up the butter and peanut butter so they’re super creamy (give it a good 3 minutes). Next, gradually work the sugar in and keep beating for another few minutes so it’s light and airy.

Stir Up the Dry Bits:

Grab a medium bowl and whisk together the flour, baking powder, baking soda, and salt so everything’s evenly spread out. Plus, it makes the flour a little puffier.

Prep Your Pans:

Fire up your oven to 350°F and grease two 9-inch cake pans well—get into the corners, too—then dust them lightly with flour so your cakes come out like a dream once baked.

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My grandma always told me a killer peanut butter cake should taste like childhood sandwiches but feel party-ready. After eating this one, she actually begged me for seconds—she claims it beats even her own legendary version.

Prep Ahead Tricks

Want to plan early? Bake the cake layers two days in advance and let them cool, wrap them up tight, and leave at room temp. You can even whip up the frosting a day ahead—pop it in the fridge sealed up. Just let it get back to room temp and beat it again before frosting for super smooth spreading.

Allergy Workarounds

If peanuts are a problem, swap in almond butter for a milder taste or sunflower seed butter to keep the nutty thing going minus the allergens. You’ll want to tweak the sugar amount a bit since some swaps aren't as sweet. For the candies, find another bright chocolate candy that fits your needs.

Tasty Pairings

This cake goes amazing with a scoop of vanilla ice cream or a cold glass of milk. Want to kick it up? Drizzle a little warm chocolate sauce over each slice right before you serve. It’s super rich, so smaller slices hit the spot. For extra yum, zap a piece in the microwave for about 10 seconds—peanut butter smells incredible warm.

Easy-Explain Texture Science

Using baking powder and soda together isn’t just for show—baking soda reacts with the buttermilk for lift, and baking powder helps out as things bake. Your cake rises just right with these two. All the fat from butter and peanut butter keeps it moist and soft, even days later.

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Frequently Asked Questions

→ Is crunchy peanut butter okay for this recipe?

Of course! Crunchy peanut butter adds texture, but choose creamy if you want smoother results in both cake and frosting.

→ Which type of M&M's is best for this cake?

Standard chocolate M&M's are classic, though peanut or mini versions can bring unique textures and tastes.

→ How should I store the finished cake?

Keep it in a sealed container at room temperature for 2 days, or refrigerate up to 5 days for longer freshness.

→ Can I swap out the peanut butter frosting?

Yes, try cream cheese frosting or chocolate ganache if you're in the mood for something different!

→ Can I prepare this cake ahead of time?

Sure thing! The layers can be baked the day before and wrapped up tightly in plastic. Frost it fresh the day you serve.

→ What if I don't have buttermilk on hand?

Mix 1/2 cup milk with 1/2 tablespoon vinegar or lemon juice. Let it sit 5 minutes before adding to your batter.