Peanut Butter M&M’s Cake

This peanut butter cake has brought so much joy to family birthdays and cozy gatherings. With its rich creamy layers dotted with colorful M&Ms and topped with lush peanut butter frosting it is pure comfort food for anyone who loves classic American treats.

I first made this for my daughter’s birthday when she asked for something “peanut buttery and pretty” and it quickly became my go to celebration cake for friends and family.

Ingredients

• All purpose flour: For reliable structure Use a fresh soft flour for best results
• Baking powder and baking soda: Help the cake rise and lighten the crumb Always check that yours are not expired
• Salt: Balances out the sweetness and enhances flavor Use fine sea salt for even mixing
• Unsalted butter at room temperature: Provides richness and a tender texture Choose a quality brand for added flavor
• Creamy peanut butter: Adds creamy nutty depth Try to use a smooth variety for best mixing
• Granulated sugar: Sweetens and adds moisture Make sure it is clump free
• Eggs: Bind everything together and give structure Use large eggs at room temperature for even blending
• Vanilla extract: Rounds out the flavors Pure vanilla brings the best aroma
• Buttermilk: Gives the cake tenderness and a delicate tang Always shake before pouring and measure carefully
• M and Ms: Add pops of chocolate and color Use fresh ones so they stay snappy and bright
• Unsalted butter for frosting: Creates a smooth creamy base as above room temperature is key
• Creamy peanut butter for frosting: Delivers maximum peanut flavor Same tips as above
• Powdered sugar for frosting: Sweetens and creates smoothness Sift if lumpy
• Heavy cream for frosting: Adds extra fluffiness and helps achieve a spreadable frosting Use full fat cold cream
• Vanilla extract for frosting: Gives aroma and balances peanut notes
• Extra M and Ms for topping: Makes the cake festive and colorful

Step by Step Instructions

Prepare the cake pans:

Grease and flour two 9 inch round pans to prevent sticking and achieve even baking

Mix the dry ingredients:

Whisk together the flour baking powder baking soda and salt in a medium bowl to ensure everything is distributed well and to aerate the mixture

Cream the butter and peanut butter:

Beat room temperature butter with peanut butter until the mixture is creamy and smooth This step makes sure the base is evenly flavored and not oily

Incorporate sugar and eggs:

Gradually beat in the sugar until the mixture is light and fluffy then add eggs one by one beating well after each addition This patience lets the batter trap more air for a tender cake

Add vanilla extract:

Stir in the vanilla to build up the aroma and unify the flavors

Alternate dry ingredients and buttermilk:

Add the flour mixture and buttermilk to the batter in turns starting and ending with flour This gradual process reduces overmixing and keeps the cake tender

Fold in M and Ms:

Gently stir in the M and Ms to avoid breaking their shells They will melt slightly in the oven giving a fun colorful effect

Divide and bake:

Evenly distribute the batter into your prepared pans and bake in the preheated oven for 25 to 30 minutes The cakes are finished when a toothpick comes out clean and the tops are golden

Cool the cakes:

Let them rest in their pans for 10 minutes then carefully transfer to a wire rack If you rush this step the cakes could crack

Prepare the frosting:

In a large bowl beat butter and peanut butter until creamy Then gradually add powdered sugar then heavy cream and vanilla and whip until everything is light fluffy and totally smooth

Assemble and frost:

Place one cooled cake layer on your serving plate Cover with frosting then top with the second cake and frost the top and sides To get a truly even finish use an offset spatula

Decorate:

Scatter extra M and Ms on top for a festive and playful finish

Save

Peanut butter is always a favorite ingredient for me because of its nostalgic creamy taste and it reminds me of after school snacks with my brother We would always sneak a spoonful when baking together and now this cake brings back those sweet simple memories with every slice

Storage Tips

Store leftover cake covered at room temperature for up to two days If your kitchen is particularly warm or humid move it to the fridge where it will keep for about four days Let refrigerated slices sit out briefly before serving for best texture The baked cake layers can be wrapped tightly and frozen for up to two months Before frosting let them thaw completely at room temperature

Ingredient Substitutions

If you are out of buttermilk you can make your own by stirring a tablespoon of lemon juice or white vinegar into a half cup of milk and letting it sit until thickened Natural style peanut butter works but must be thoroughly stirred to avoid oil separation If you want a nut free treat use sunflower seed butter and swap M and Ms for a safe chocolate candy

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Serving Suggestions

Serve generous slices with a cold glass of milk or a scoop of vanilla ice cream For a birthday hit add candles and a colorful sprinkle medley along with the M and Ms The cake can also be baked as cupcakes just reduce the bake time to fifteen to eighteen minutes

Recipe FAQs

→ How do I ensure the cake stays moist?

Use buttermilk and room-temperature butter for a tender, moist crumb. Avoid over-baking by checking with a toothpick.

→ Can I use natural peanut butter?

Creamy peanut butter with stabilizers works best to achieve a smooth texture, but natural versions may be used if well stirred.

→ How should I store leftovers?

Keep the cake covered in an airtight container at room temperature for up to two days, or refrigerate for longer freshness.

→ Can different candies be substituted for M&M’s?

Yes, try mini chocolate chips, Reese’s Pieces, or chopped peanut butter cups for a fun variation in flavor and color.

→ How do I achieve a smooth frosting?

Beat the butter and peanut butter well before gradually adding powdered sugar and heavy cream for a fluffy, spreadable consistency.