Preliminary note: I in no way condone J.K. Rowling or her hurtful anti-trans sentiments. I believe in the power of stories and that books belong to their community of readers. I have made a commitment never to purchase merchandise, materials, or access to experiences (like Harry Potter World) that may financially benefit J.K. Rowling in anyway.
I’ve been working on these for a while. Since I started this Harry Potter recipes development project, I have been thinking about what cauldron cakes from the wizarding world would look and taste like. I mean, except for the name, they’re never given much of a literary description. In searching the internet for other people’s interpretations, I found a lot of chocolate and overturned cupcakes–honestly, those just didn’t do it for me, and I thought I could do better.
Let’s start with the shape. The reason this recipe took me so long was my search for the perfect baking mold. I didn’t want to make just another ill-disguised upside down cupcake or a cake carved vaguely into the shape of–what is that? a lump? No, I wanted these to be pristine little half-domes with a clean, smooth coating. You know, like a cauldron. My solution: silicone. I bought these molds from the crafting store and started experimenting. I had used silicone for chocolate and Bavarian creams in culinary school, but never baking. Turns out, these silicone molds are not as nonstick as their cousins, Silpats, would have you believe. My first batch of cakes completely tore apart as I tried to remove them from their divots. Lesson learned–grease and flour them, and give your cakes plenty of time to chill in the molds before releasing them for clean shapes.
In the Harry Potter books, chocolate is found in the forms of frogs and wands and in big blocks (in case of Dementors, duh), plus Chocolate Cauldrons are specifically called out as the magical equivalent to filled truffles. Since cauldrons already have a chocolate version, I went another way for the flavoring: blackberry and lemon. The lemon curd topping makes these little cauldrons look like they’re filled with bright, golden Felix Felicis, but you could switch it up with whatever “potion” (okay, okay–jam or other sweet spread) you choose. The blackberry cake holds its vivid purple color exceptionally well during baking and is a charming little surprise after you bite through the chocolate coating.
Speaking of the coating, these little cauldrons are encased with white chocolate colored with–wait for it–charcoal. And you thought that fad was over. Yes, you can totally use a black gel food coloring but where’s the fun in decorating if you’re not cautiously twisting open activated charcoal capsules that you got in the supplements aisle, praying that you don’t stain anything in your kitchen black (again)? It’s a fun ingredient to use for adding natural coloring to food, even if it’s super unnecessary as a health supplement. It has the added bonus of creating a matte finish, which adds a lot of authenticity to the cauldrons.
Overall, these little cakes were unbelievably adorable and I couldn’t stop looking at them. Even my SO couldn’t keep the smile off his face when he admitted that they were “pretty cute.” Yes, the recipe is a bit of a project, but it could be simplified by using a boxed cake mix (either pre-flavored or with the homemade juice mixture stirred in). The blackberry and lemon together create a wonderful balance of fruity sweetness and tart citrus, but the cauldrons could be recreated with different flavor combos (strawberry cake instead of blackberry, chocolate cake with caramel sauce “potion,” yellow cake with cherry preserves, the list goes on). Even with my imperfect chocolate piping skills, they were forgiving enough to be one of the most enjoyable baking projects I’ve done in a long time.
But anyway, enough talking! Let’s get to it:
Cauldron Cakes Recipe
Cake Recipe Inspiration: Stella Parks’s Classic Vanilla Butter Cake on Serious Eats
Makes about 30 cauldron cakes
- 1 (16 oz.) bag frozen blackberries
- 1 cup water
- 1/2 cup reserved blackberry juice
- 2 Tbsp. whole milk, room temperature
- 5.3 oz. granulated sugar (150 grams; about 3/4 cup)
- 3 oz. unsalted butter, room temperature (85 grams; 6 Tbsp.)
- 1 1/2 tsp. baking powder
- 3/4 tsp. kosher salt
- 1 egg, room temperature
- 1 tsp. vanilla extract
- 5.3 oz. all-purpose flour (150 grams; about 1 cup plus 2 1/2 Tbsp.), plus extra for flouring molds
- Combine blackberries and water in a medium pot. Bring to a boil over medium-high heat and cook uncovered until berries are broken down and juice is reduced and thick, about 30 minutes, stirring frequently.
- Filter out fruit solids through a fine-mesh sieve, pressing to extract juice. You should have just over ½ cup juice. It’s okay if yours didn’t reduce exactly to 1/2 cup. If you have over 1 cup, simmer juice for 10 to 15 more minutes to reduce further. If your juice reduced too much, add water until you have 1/2 cup.
- Let juice cool completely at room temperature.
- Preheat oven to 350°F. Grease silicone molds with nonstick cooking spray and sprinkle generously with flour to coat. Gently shake out excess flour, then place prepared silicone molds right-side up on a baking sheet and set aside.
- Combine blackberry juice and milk and set aside.
- Combine sugar, butter, baking powder, and salt in the bowl of a stand mixer with the paddle attachment (or use a handheld electric mixer). Beat on medium speed until light and aerated, about 5 minutes, scraping the bowl with a rubber spatula halfway through.
- Add egg and vanilla to sugar mixture and continue beating until fully incorporated.
- Add a third of the flour and mix on low until combined. With the mixer running, drizzle in a third of the juice mixture. Repeat with alternating thirds of flour and juice until all ingredients have been incorporated, stopping to scrape the bowl with a rubber spatula as necessary.
- Do a final scrape of the mixing bowl with to ensure all flour has been incorporated into the batter. Fill each of the silicone molds with 1 scant tablespoon of the cake batter*.
- Bake for 11 to 15 minutes, or until a toothpick inserted into the center of several of the cakes comes out clean.
- Let cakes cool at room temperature for at least 15 minutes, then transfer to the freezer and chill for at least 1 hour. Carefully push cakes out of the molds and keep refrigerated until ready to decorate.
- Repeat baking and cooling process with remaining batter**.
Assembly & Decoration
- Place white chocolate wafers in a medium glass bowl. Heat in the microwave until chocolate is melted, about 1 to 2 minutes, stirring every 15 to 30 seconds.
- Carefully open charcoal capsules over white chocolate and stir to incorporate the powder (discard the capsule shells). Add charcoal (or gel food coloring) until the desired color of gray or black is reached.
- Pour chocolate mixture into a pastry bag or resealable zip-top bag and snip a small opening in the corner to pipe.
- Using the cleaned and dried silicone mold, pipe about 1 1/2 tsp. of chocolate coating into each space. Press chilled cakes gently into coating, just until the chocolate comes up flush to the top. Work quickly, as chocolate coating can set in the piping bag after several minutes (if this happens, reheat briefly in the microwave).
- Pipe a lip/edge onto the top of the “cauldron” with chocolate. Let coating set, about 5 minutes, before carefully pushing cauldrons out of the mold.
- If desired, lay out a piece of wax or parchment paper and pipe a small “X” formation that will act as the cauldron feet. Set the cake on top of the “X” and let chocolate set before peeling off of paper.
- Onto the top of each cauldron, spoon or pipe lemon curd (or jam “potion” of choice). You could also add sugar pearl sprinkles to emulate bubbles or any other decorations of your choice.
- Store cakes at room temperature for up to 6 hours and in the refrigerator for up to 1 week.
*My silicone molds held 2 Tbsp. of filling. If you have a differently sized mold, fill each divot about halfway.
**This recipe yields enough batter to make about 30 (1 Tbsp.) cakes, or enough for two molds. If you don’t have two molds (I don’t either), refrigerate the batter while you wait for the first cakes to bake and chill. Let the batter sit at room temperature for at least 15 minutes before baking the second batch. Alternatively–just make cupcakes with the remaining batter, cut out the centers, and fill with lemon curd before frosting or dipping the bottoms in chocolate coating. They’re like extra-capacity cauldrons!
***I used activated charcoal from the supplements aisle and twisted open the capsules to pour out the charcoal. You can also find powdered charcoal which you can sprinkle in, 1/4 tsp. at a time. Be careful not to get this charcoal on any plastic, wood, or clothing—it will stain. Don’t want to mess with charcoal? No shame. Black or gray gel coloring would work just as well.