This brownie cupcake recipe is for chocolate lovers: tender, moist, and delightfully fudgy. They’re finished with a glossy, smooth, not-too-sweet sour cream chocolate frosting that balances the rich cake perfectly.
The inspiration and recipe testing
These brownie cupcakes went through several iterations before arriving at the final version. The first attempt started as brownie cheesecake muffins and didn’t go as planned. After that I tried plain brownie muffins, which turned out moist and tasty but didn’t rise the way I wanted. Finally I aimed for cupcakes—flat tops that are ideal for frosting—and refined the batter until the texture and rise were just right.
The frosting had its own set of mishaps. My initial plan included melted chocolate folded into a sour cream frosting, but when I tried tempering the chocolate with sour cream it seized. After some experimentation I discovered the frosting is excellent without melted chocolate—silky, glossy, and quick to make, with no extended chilling required. With multiple trials and adjustments, the recipe became a keeper.
Sour cream chocolate frosting
If you prefer something less sweet than classic buttercream, this sour cream chocolate frosting is worth trying. It uses less powdered sugar and more cocoa for a deeper chocolate flavor, while the sour cream adds a subtle tang and a silky, glossy finish. The tanginess balances the sweetness without tasting like straight sour cream—it’s velvety and rich, and most people won’t guess there’s sour cream in it.
How to bake perfect brownie cupcakes
Bake time determines texture: a slightly underbaked cupcake yields a fudgier center, while a longer bake produces a more cake-like crumb. Avoid overbaking—if a skewer comes out completely clean, the cupcakes will be dry after cooling. The ideal test is a skewer with moist crumbs but no wet batter. Allow the cupcakes to cool completely in the pan; residual heat continues cooking them gently and helps achieve a fudgy interior.
How to make brownie cupcakes
1. Melt butter and add the chocolate. Combine hot melted butter with chopped chocolate until smooth. Let the mixture cool slightly while you prepare the remaining ingredients.
2. Whisk eggs and sugars. There are no baking powder or soda agents in this recipe: the rise comes from air incorporated into the eggs. Beat eggs with granulated and brown sugar until the sugar dissolves and the mixture lightens in color. Rubbing a bit between your fingers is the best check—there should be no graininess.
3. Add the cooled butter–chocolate mixture, cocoa, vanilla, oil, and salt. Whisk until combined. 4. Fold in flour and chocolate chips just until the batter is streak-free—do not overmix. 5. Portion into a cupcake tin and bake. Line the tin with paper liners or grease and flour the cups. Fill each cup about ¾ full.
6. Cool completely in the pan to room temperature before removing the cupcakes to a wire rack. If you underbaked for a fudgier center, the top may sink slightly as it cools—this is normal. 7. Make the sour cream frosting: it comes together quickly in two steps:
- Cut cold butter into powdered sugar and cocoa. The dry mix will look crumbly; aim for small butter pieces but a few larger bits are okay.
- Beat in vanilla, salt, and sour cream. Add sour cream in two additions and whip until smooth and fluffy for a silky finish.
8. Frost your cooled cupcakes. The frosting holds shape well while remaining soft and glossy.
How to decorate brownie cupcakes
This frosting behaves like a hybrid between cream cheese frosting and buttercream: smooth, glossy, and stable enough to pipe. For a quick finish, place a dollop and swirl with a knife for a soft, rustic look. Finish with chocolate shavings, sprinkles, or flaky sea salt according to your preference.
Storage
Store the cupcakes covered to prevent drying. Unfrosted, they keep about 4 days at room temperature; frosted cupcakes will last up to one week refrigerated. If chilled, let them sit at room temperature for about 30 minutes before serving so the frosting softens and the texture improves.
Other recipes to try
Try variations like lemon brownies, chocolate chip cookie brownies, brown butter brownies, or red velvet brownies for different flavor profiles.
If you try this recipe, please leave a comment and review—feedback is always welcome. Tag your creations on social media so others can see your results.
Brownie Cupcakes with Sour Cream Chocolate Frosting Recipe
- Author: Mimi
- Total Time: 1 hour 40 minutes
- Yield: 12 cupcakes
Description
Rich and fudgy brownie cupcakes covered in a silky, glossy chocolate frosting made with sour cream. The frosting is balanced and not overly sweet, making it an ideal complement to the deep chocolate cupcakes.
Ingredients
For the brownies:
- ½ cup (115g) unsalted butter
- 6 ounces (170g) chopped semi-sweet chocolate, good quality
- ¾ cup (150g) granulated sugar
- ½ cup (100g) packed brown sugar (light or dark)
- 3 large eggs, at room temperature
- 1 teaspoon pure vanilla extract
- ½ cup (40g) unsweetened cocoa powder
- 2 tablespoons neutral vegetable oil
- ½ cup + 2 tablespoons (80g) all-purpose flour, spooned and leveled
- ¼ teaspoon salt
- ½ cup (85g) semi-sweet chocolate chips (optional)
For the chocolate sour cream frosting:
- ½ cup (115g) unsalted butter, softened
- 1 cup (130g) powdered sugar
- ½ cup (40g) unsweetened cocoa powder
- ¼ teaspoon salt
- 1 teaspoon pure vanilla extract
- ½ cup (120g) full-fat sour cream, at room temperature
- Chocolate shavings, sprinkles, or flaky sea salt for decorating (optional)
Instructions
Make the brownies:
- Preheat oven to 350°F (175°C). Line a standard 12-cup cupcake tin with paper liners or grease and dust with flour.
- Melt the butter in a small saucepan over medium heat, then remove from heat.
- Add the chopped chocolate to the hot butter and whisk until completely melted and smooth. If some pieces remain, return briefly to very low heat to finish melting. Let cool slightly.
- Beat the eggs and sugars together in a large bowl with an electric mixer using the whisk attachment until the sugar dissolves and the mixture lightens in color (about 5–7 minutes). It should not feel gritty when rubbed between your fingers.
- Stir in vanilla, cocoa, oil, and the cooled chocolate–butter mixture until combined.
- Fold in flour, salt, and chocolate chips just until the batter is uniform and streak-free. Do not overmix.
- Fill the cupcake cups about ¾ full with batter.
- Bake in the center of the oven for 15–20 minutes, until the tops are crackly and a skewer comes out with a few moist crumbs. If you prefer fudgy centers, err on the shorter end of the time.
- Cool completely in the tin before removing to a rack and frosting.
Make the sour cream frosting:
- Cut the butter into the powdered sugar and cocoa using a mixer with the paddle attachment until the mixture resembles fine crumbs.
- Add vanilla, salt, and half the sour cream and mix to combine. Add the remaining sour cream and whip on high until light and fluffy, about 1–2 minutes.
- Frost the cooled cupcakes and decorate with chocolate shavings, sprinkles, or flaky sea salt as desired.
Notes
I recommend using baking or couverture-style chocolate for smooth melting, but high-quality or good-value chocolate both work—just chop it evenly for consistent melting.
- Prep Time: 25 minutes
- Bake Time: 15 minutes
Enjoy!