These cupcakes are a long-standing favorite of mine! My favorite chocolate cake, filled with rich salted caramel sauce, and topped with a silky smooth caramel Swiss meringue buttercream. Yum! I don’t make these as often as I should, probably because they are a bit more involved (read: time consuming), but the nice thing is you can absolutely make these over the course of a few days. The caramel sauce can be made ahead of time, and will keep in the fridge for a while. Then, you can make the cupcakes one day, and fill & frost the next! Spreading these out over a 3 day period would certainly make the process a bit easier – I’m sure I can find a reason to make them again sometime soon
The caramel sauce recipe will make more than you need to fill the cupcakes – which is never a bad thing. Store it in your fridge and use it on top of some ice cream (or eat it with a spoon… no judgment here ).
For the cupcakes:
- ½ cup plus 1 tbsp. (1 5/8 oz.) Dutch-process cocoa powder
- ½ cup plus 1 tbsp. hot water
- 2¼ cups (9 5/8 oz.) all-purpose flour
- ¾ tsp. baking soda
- ¾ tsp. baking powder
- ½ tsp. salt
- 2 sticks plus 1 tablespoon unsalted butter, at room temperature
- 1 2/3 cups (11 3/4 oz.) sugar
- 3 large eggs, at room temperature
- 1 tbsp. vanilla extract
- ¾ cup sour cream
For the caramel sauce:
- 1 cup (7 oz.) sugar
- 1¼ cups heavy cream
- 1 vanilla bean, split lengthwise
- ¼ tsp. coarse salt
- ½ tsp. vanilla extract
For the frosting:
- 1¼ cup sugar, divided
- 5 tbsp. water
- 5 tbsp. heavy cream
- Generous pinch of sea salt, such as fleur de sel
- 5 large egg whites
- 3¾ sticks (30 tbsp.) unsalted butter, at room temperature
To make the cupcakes, preheat the oven to 350˚ F. Line 2 cupcake pans with paper liners. In a small bowl or liquid measuring cup, combine the cocoa powder and hot water and stir until fully combined. In another bowl whisk together the flour, baking soda, baking powder, and salt.
In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar on medium-high speed until fluffy, about 3 minutes. Add the eggs one at a time, mixing well after each addition and scraping down the sides of the bowl as needed. Blend in the vanilla and then the cocoa mixture until fully combined. With the mixer on low speed, add the flour mixture in three additions alternating with the sour cream, beginning and ending with the dry ingredients and mixing each addition just until incorporated (so flour, sour cream, flour, sour cream, flour).
Divide the batter evenly between the prepared liners, filling each about 2/3 full. (In my experience these cupcakes tend to rise a LOT, so err on the side of under-filling the liners). Bake for about 18-20 minutes, or until a toothpick inserted into the center of a cupcake comes out clean, rotating the pans halfway through baking. Let cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.
To make the caramel sauce, measure out the heavy cream in a liquid measuring cup and scrape the seeds from the vanilla bean into the cream. Set aside.
Spread the sugar in an even layer over the bottom of a large, heavy-bottomed saucepan. Heat over medium-low heat, making sure to keep a close eye on it. When the sugar begins to liquefy around the edges, use a heatproof spatula to gently push the edges towards the center. Continue to do so until all the sugar is melted, being careful not to mess with the sugar too much – if you do so it will start to clump together. Once the caramel reaches a deep amber color, immediately remove the sauce pan from the heat. (To test the color, you can spoon a little bit onto a white plate.) Slowly and carefully whisk in half of the heavy cream along with the vanilla bean seeds, whisking constantly. The mixture will steam and bubble violently. Continue to stir until the cream is well incorporated, then whisk in the remaining cream. Stir in the salt and the vanilla. If any sugar has hardened, place the saucepan over low heat and whisk until smooth. Set aside to cool slightly, until cool enough to handle.
To make the frosting, place ½ cup plus 2 tablespoons (4 3/8 oz.) of the sugar in a medium, heavy-bottomed saucepan. Stir in the water. Bring the mixture to a boil over medium heat. Stop stirring and let the caramel cook, gently swirling from time to time, until it is a deep amber color, watching it carefully (it can go from delicious caramel to burnt in a matter of seconds). Remove the mixture from the heat and slowly whisk in the cream and then the salt as above. Set aside and let cool.
Combine the egg whites and the remaining ¼ cup plus 2 tablespoons (2 5/8 oz.) sugar in a heatproof bowl (I use the bowl of my stand mixer) set over a pot of simmering water. Heat, whisking frequently, until the mixture reaches 160° F on an instant-read thermometer and the sugar has all dissolved. If not already using your stand mixer bowl, transfer the mixture to that and fit your mixer with the whisk attachment. Beat on medium-high speed until stiff peaks form and the mixture has cooled to room temperature, about 8 minutes. The outside of the bowl should be cool to the touch.
Reduce the mixer’s speed to medium and add the butter, 2 tablespoons at a time, adding more once each addition has been incorporated. If the frosting looks soupy or curdled, continue to beat on medium-high speed until thick and smooth again, about 3-5 minutes more. This may take longer – just keep mixing! I promise it will come together! Blend in the cooled caramel until smooth and completely incorporated, scraping down the sides of the bowl as needed.
Fill your cupcakes with the caramel sauce, either by cutting a core out of the center or by using a pastry bag and an injection tip. Transfer the frosting to a pastry bag and frost as desired. If you’d like, top the cupcakes with a salted caramel candy – this should be done immediately before serving as homemade caramels will start to melt into the frosting pretty quickly.
Yield: 2 dozen cupcakes