Banana Cupcakes with Peanut Butter Frosting

From the kitchen of Carly

Soft, deeply banana-forward cupcakes with a tender crumb from sour cream, topped with creamy peanut butter frosting. These hit that sweet spot between cake and comfort food, perfect for lunch boxes or afternoon cravings when you want something homemade that actually tastes like real fruit.

Banana Cupcakes with Peanut Butter Frosting

Banana and peanut butter were made for each other, and these cupcakes prove it. The trick is very ripe bananas (almost brown) for real flavor, plus a kiss of sour cream to keep the crumb tender and faintly tangy. The frosting is pure indulgence, creamy and balanced, never cloying. These stay moist and delicious for days.

Prep
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Cook
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Total
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Servings
4
Difficulty
medium

Ingredients

4 servings

  • 1 1/4 cupall purpose flour
  • 1 1/2 tspbaking powder
  • 1/2 tspbaking soda
  • 1/4 tspsalt
  • 2very ripe large bananas, peeled
  • 1/2 cupsour cream
  • 1 1/2 tspvanilla extract
  • 3/4 cupsugar
  • 1/2 cupunsalted butter, room temperature
  • 1 largeegg
  • 1 largeegg yolk
  • 1 1/2 cuppowdered sugar
  • 18-ounce package cream cheese, room temperature
  • 1/2 cupunsalted butter, room temperature
  • 1/2 cupsmooth peanut butter
  • 1Chopped lightly salted roasted peanuts

Instructions

  1. Set a rack in the center of the oven and heat it to 350°F. Line 12 standard muffin cups (1/3-cup capacity) with paper liners. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. In a separate medium bowl, mash the bananas with a fork until smooth, then mix in the sour cream and vanilla.

  2. Beat the sugar and butter in a large bowl with an electric mixer until light and fluffy, about 3 minutes. Add the egg and egg yolk and beat until well combined. With the mixer on low, add the flour mixture in 3 additions, alternating with the banana-sour cream mixture in 2 additions, starting and ending with the flour and beating just until blended after each addition. Divide the batter evenly among the prepared muffin cups, a generous 1/4 cup per cavity.

  3. Bake until a tester inserted into the center of each cupcake comes out clean, about 20 minutes. Transfer the cupcakes to a wire rack and let them cool completely before frosting.

  4. Sift the powdered sugar into a large bowl, then add the cream cheese, butter, and peanut butter. Using an electric mixer, beat everything together until smooth and creamy. Spread the frosting evenly over the tops of the cooled cupcakes, then scatter over chopped peanuts if you like.

Tips from the kitchen

  • Mash bananas aggressively until completely smooth, no lumps. Underripe bananas will give you bland cupcakes with zero personality.
  • Don't skip room temperature butter and cream cheese for the frosting. Cold ingredients won't cream properly, and you'll end up with a grainy, broken mess.
  • Fill muffin cups generously (about 3/4 full) so the cupcakes bake evenly and dome nicely. Underf filling means flat, sad cakes.
  • Use smooth peanut butter only. Natural or old-fashioned varieties have too much oil and won't hold the frosting structure you need.

Variations

  • Chocolate banana: Swap 1/4 cup flour for 1/4 cup unsweetened cocoa powder, whisk it into the dry ingredients, and frost with the peanut butter frosting as is.
  • Honey peanut butter frosting: Replace 2 tablespoons of the powdered sugar with 2 tablespoons of honey for a softer, slightly less sweet frosting with more complexity.
  • Brown butter: Brown the cupcake butter first (let it cool), then proceed. It adds a toasty, nutty depth that complements the peanut butter beautifully.
  • Chunky peanut butter frosting: Use chunky peanut butter instead of smooth for texture contrast, and skip the peanut garnish on top.

Make ahead and storage

Store covered at room temperature for up to 3 days, or refrigerate for 5 days. Freezing is fine for up to 2 months (wrap individually), but eat them at room temperature for the best frosting texture.