Chocolate Cupcakes with Peanut Butter Banana Filling are a delicious triage of chocolate, peanut butter, and banana flavor. A moist chocolate cupcake is filled with a peanut butter banana custard filling, then frosted with a peanut butter buttercream.
Last week, I did a presentation at my school about this blog. My school’s kinda tiny and a little unique, so people have opportunities to share cool stuff they do. So, I decided telling roughly 300 people about my blog would be great publicity.
I thought I was awkward because it involved me talking about myself for like ten minutes and while I excel at other things, talking about myself is always super awkward. But I was told it was an awesome presentation.
The free samples I gave out probably helped. I’m now the school’s resident baker and So. Many. People. have asked me to bake for them. I’ve gotten stopped in the hallways too many times to count and asked “Omg, can you make me those kit-kat brownies? I’ll pay you.” Or, “Can you bake cookies for the school one day, I’ll pay you.” Or, “How much would it cost for you to bake a cake?”
It’s great, and I love it. By senior year I hope to basically fulfill all baking needs the school has. And hopefully they will have a lot of baking needs.
Anyways, these Chocolate Cupcakes with Peanut Butter Banana Filling were for the winner of a little contest I did. In my presentation, I said that anyone who liked our Facebook page before midnight that night would be entered in a drawing for a custom batch of cupcakes. Over 70 people liked it and our page likes were raised by over 50%. I felt the love.
When I asked the winner what he wanted, he immediately and without hesitation said, “Banana!” But the people around him thought that was ridiculous. (“You get custom cupcakes and you choose banana?”) Eventually, we ended up with chocolate and peanut butter… But I kind of wanted to prove those people who ridiculed banana wrong. Banana can be delicious. So, I decided on a banana peanut butter custard filling.
The banana filling really elevated these Chocolate Cupcakes with Peanut Butter Banana Filling from average chocolate and peanut butter cupcakes to something unique and interesting and just better. The kid loved them and shared them with a bunch of people and they all raved about them.
A British kid said, “They were so good, with peanut butt-ah and banan-er” and it was the highlight of my day. Possibly week.
-Audrey
PrintChocolate Cupcakes with Peanut Butter Banana Filling
- Prep Time: 1 hour
- Cook Time: 40 minutes
- Total Time: 3 hours (including cooling time)
- Yield: 12 cupcakes 1x
Ingredients
Chocolate Cupcakes
- 1/2 cup (1 stick) unsalted butter
- 2 ounces semi-sweet baking chocolate
- 1/2 cup unsweetened cocoa powder
- 3/4 cup (95g) all-purpose flour
- 1/2 teaspoon baking soda
- 3/4 teaspoon baking powder
- 1/4 teaspoon salt
- 2 large eggs, at room temperature
- 1/2 cup granulated sugar
- 1/4 cup light brown sugar
- 1 teaspoon vanilla extract
- 1/2 cup buttermilk
Peanut Butter Banana Custard Filling
- 1/4 cup sugar
- 1 ½ tbsp cornstarch
- 1 eggs yolk
- 2 egg yolks
- 2 tbls + 2 tsps peanut butter
- 1 cups whole milk
- 1 tsp vanilla extract
- Half a heavy pinch of kosher salt
- 1 1/2 large bananas, sliced
Peanut Butter Frosting
- 1 cup creamy peanut butter
- 8 Tbsp (1 stick) butter, at room temperature
- 2 cup confectioners’ sugar, sifted
- 3 to 4 Tbsp milk
- 2 tsp pure vanilla extract
Instructions
Make the cupcakes:
- For the cupcakes: Preheat the oven to 350F degrees. Line a 12-cup cupcake/muffin pan with cupcake liners. Set aside.
- Melt the butter and chocolate together in the microwave. Microwave in 30 second increments, stirring between each time. You may also melt the butter and chocolate over low heat on the stovetop. Stir until smooth and set aside to slightly cool.
- In a medium sized bowl, toss the cocoa powder, flour, baking soda, baking powder, and salt together until thoroughly combined. Set aside. In a large bowl, whisk the eggs, sugar, brown sugar, and vanilla together until smooth. Add the cooled butter/chocolate and whisk until smooth. Add half of the flour mixture, then half of the buttermilk. Repeat until everything is added. Stir until *just* combined; do not overmix. The batter will be very thick like pudding.
- Divide the batter between 12 liners in your cupcake pan. Bake for 18 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool completely before frosting.
Make the custard:
- Bring the milk and sliced bananas to a boil in a large saucepan. If you’re using vanilla extract, just leave it out for now. Turn off the heat, and allow the mixture to steep until cool. You can also do what I did, and store it in the refrigerator overnight for extra banana flavor.
- When you’re ready to continue, bring the milk back to a simmer. Strain the mixture through a fine mesh sieve, pressing lightly to ensure you’re getting out as much liquid as possible, but not so much that you’re pressing the banana solids through the sieve. Check to make sure you have 2 cups of milk; if not, add a little milk until you’re back up to 2 cups.
- In a mixing bowl, whisk together the egg and yolks together with the reserved vanilla caviar or vanilla extract (if using extract instead of whole vanilla bean), sugar, cornstarch, and salt. Slowly drizzle in the hot milk, whisking constantly, until you’ve incorporated at least half of it. Then add the tempered egg mixture back into the hot milk on the stove, whisking constantly. Continue whisking the egg mixture over medium heat until it’s very thick and begins to bubble. Once it begins to bubble, continue to cook for another minute.
- Pour the mixture into the bowl of a stand mixer fitted with the paddle attachment and beat at low speed until the cream has cooled enough so that the mixing bowl is neutral to the touch. Add the peanut butter, and continue to beat at medium speed until well combined, scraping the paddle and the sides of the bowl as needed.
- Scrape the custard into an airtight container (you can press plastic wrap into the top to prevent a skin from forming), and refrigerate until ready to use. I used a resealable bag, which had the added bonus of allowing me to simply snip off a corner of the bag and pipe the custard directly onto the cake when I was ready to do final assembly.
Make the frosting:
- Place the peanut butter and butter in a large mixing bowl. Blend with an electric mixer on low speed until fluffy, 30 seconds.
- Stop the machine. Add the confectioners’ sugar, 3 tablespoons milk, and the vanilla. Blend with the mixer on low speed until the sugar is well combined, 1 minute.
- Increase the speed to medium and beat until the frosting lightens and is fluffy, 1 minute more. Blend in up to 1 tablespoon milk if the frosting seems too stiff.