Dementor Cookies are dark, wonderfully dramatic, perfectly spooky, and ridiculously easy to make.
The cookie itself is a flavorful double chocolate chip cookie made in one bowl, with a whole marshmallow stuffed right into the center.
The idea is that these cookies channel the vibes (visually only!) of a Dementor … but, you know, one you actually want around you.
Serve these cookies for a Harry Potter movie marathon, Halloween party, themed birthday, or just a fun night in with other HP nerds like us.
Just don’t expect your Patronus to protect you from eating the whole batch!
What Are Dementor Cookies?
These cookies were inspired by the Dementors from Harry Potter … something you probably already knew if you’re here! As a millennial, I grew up with the Harry Potter franchise, and I still love re-binging the movies yearly to this day.
I thought long and hard about what I wanted my first “ode to Harry Potter in cookie form” to be. There are already a ton of “sorting hat” and “butterbeer” cookies out there. And lately, my ‘schtick’ has been stuffing cookie dough with a marshmallow.
So, despite the risk of becoming a one-trick pony, here we are again; stuffing delicious yet simple cookie dough with a whole marshmallow.
And I’m zero percent mad about it lol.
Why You’ll Love These Harry Potter-Inspired Cookies:
- They’re made in just one bowl. Less cleanup is literally always a win.
- They taste like Oreos. Black cocoa gives the dough its dramatic color and a mildly chocolatey flavor reminiscent of Oreos.
- Thick and chewy. Cold butter and a slightly hotter oven help keep the cookies perfectly thick, instead of sad and thin.
- The marshmallow does the decorating for you. No piping bags, royal icing, or artistic abilities required. Just simple fun that’s ready to enjoy in no time!
- They’re delightfully nerdy. But, as Harry Potter fans, aren’t we also delightfully nerdy? I think so.
- Prison Mike would love (hate?) these cookies. If you’re a fan of The Office, you’ll get what I mean. If you’re not … don’t worry about it lol.
What Is Black Cocoa?
Black cocoa is an ultra-Dutch-processed cocoa powder that’s been alkalized more than natural cocoa powder. That process dramatically darkens the cocoa, giving it that nearly-black color and a unique chocolate flavor that’s less rich than most cocoa powder gives double chocolate cookies. Black cocoa is also what gives Oreos their distinctive flavor!
That characteristic dark color makes it perfect for these Dementor Cookies.
Cocoa Powder Substitutions
Dutch-processed cocoa powder is alkalized almost as much as black cocoa powder, so that would be the best substitution here.
Unsweetened aka natural cocoa powder is more acidic, so it needs baking soda to react and rise – and because this recipe uses both baking soda and baking powder, you can use that too, if needed.
You can substitute either type of cocoa powder at a 1:1 ratio, but you’ll lose the dramatic color and Oreo-like flavor, and your cookies will be more chocolate-forward.
The Marshmallow
The large marshmallow in the center is there for deliciousness, of course, but also for maximum Dementor vibes.
As the cookies bake, the marshmallow peeks out of the dough more and more, creating white patches against the dark cookie, for a fun, unique, spooky appearance, artistically reminiscent of scary Dementors.
How to Stuff the Cookies
- Portion the dough using a large 3-Tablespoon cookie scoop.
- Flatten each ball of dough into a disc using your fingers.
- Place a full marshmallow in the center, then wrap the dough around it, leaving a little bit of marshmallow exposed at the top.
- Bake and enjoy the fun!
Baking Science Moments:
- Cold butter slows down spreading: Butter begins melting as cookies bake. Starting with cold butter means it takes longer for that butter to melt completely, so the dough has a little more time to begin setting before the fat fully liquefies, helping the cookies hold onto more of their height.
- A higher oven temperature helps set the edges: Baking these cookies at 375°F / 190°C helps the outside begin setting relatively quickly, so you get perfectly crisp edges while the middle stays softer and chewier.
- The right amount of flour, sugar, fat, and leavening: Baking is chemistry, and the ratios of these ingredients are crucial for the thickness, chewiness, and overall texture of these cookies. That’s why measuring precisely is so important! Learn more in my Kiersten’s Baking Tips post here.
How to Store Dementor Cookies
Store completely-cooled Dementor Cookies inside an airtight container at room temperature for about 4 days.
Because marshmallow can become a little sticky as it sits, I recommend placing parchment between layers if you’re stacking them.
Dementor Cookies Frequently Asked Questions
What Chocolate Chips Should I Use?
You can use any mix-ins you like here! I usually use semi-sweet chocolate chips because they balance the sweetness of the marshmallow perfectly.
Alternatively, use dark chocolate, milk chocolate, chocolate chunks, peanut butter chips, or M&Ms – you name it, it’ll work here at a 1:1 ratio. Just note that the sweeter the mix-in, the sweeter the cookies will taste.
Can I Make These Without Marshmallows?
I highly recommend using marshmallows. That bright white center against the dark cookie is what makes the theme recognizable without requiring any complicated decorating.
If you don’t have any large marshmallows, feel free to stuff with 4-5 mini marshmallows, or several white chocolate chips instead, for similar vibes.
What Makes These Cookies Look Like Dementors?
The black cocoa cookie dough contrasts with the bright white marshmallow in the center. As the cookie bakes and the marshmallow peeks out, irregular cracks and ripples form, making the cookies look like little floating, ragged Dementors.
Sure, they’re not exactly a perfect Dementor-y replica – but for an easy 1-bowl recipe that doesn’t need any special decorating or icing, it’s a pretty good ‘artistic rendering’ of the Dementors we all fear from HP!
Can I Use Regular Cocoa Powder Instead of Black Cocoa?
You can substitute the black cocoa for any type of cocoa powder at a 1:1 ratio, but you’ll lose the dramatic color and Oreo-like flavor, and your cookies will be more chocolate-forward and rich in flavor.
More Fandom Baking You May Enjoy:
- Rocky Cookies – Inspired by Project Hail Mary
- Spider-Man Inspired Cookies
- Parks & Recreation-Inspired Cookies
- Chocolate ‘Upside Down’ Cake – Inspired by Stranger Things
Dementor Cookies Inspired by Harry Potter
Ingredients
- 226 grams (2 sticks) unsalted butter, cold and cubed
- 250 grams (1 ¼ cups) light brown sugar
- 100 grams (½ cup) granulated sugar
- 1 Tablespoon vanilla extract
- 2 large eggs PLUS 1 extra yolk, separated when cold, then brought to room temp
- 310 grams (2 ¼ cups + 1 Tablespoon) all-purpose flour, measured accurately
- 65 grams (¾ cup) black cocoa powder*
- 1 ¼ teaspoons baking powder
- ½ teaspoon baking soda
- ½ teaspoon salt
- 225 grams (1½ cup) semi-sweet chocolate chips, plus more for topping, optional
- 20 large marshmallows
- Flaky sea salt, for topping
Instructions
- Preheat oven to 375°F / 190°C. Line light-colored rimmed baking sheets with parchment paper.
- In the bowl of a stand mixer fitted with the paddle attachment, place the cold, cubed butter, light brown sugar, and granulated sugar. Start mixing on low and slowly increase to medium-high until light, fluffy, and slightly lightened in color – about 5 minutes. Stop once or twice during this time to scrape down the bottom and sides of the bowl.
- Add the eggs, egg yolk, and vanilla extract. Mix on medium until incorporated, about 1 minute. Scrape down the sides and the bottom of the bowl well.
- Add the flour, black cocoa powder, baking powder, baking soda, and salt. Mix on low until almost incorporated. Scrape down the sides and bottom of the bowl thoroughly.
- Add the chocolate chips. Mix on low until just combined.
- Using a large 3-Tablespoon spring-loaded cookie scoop, portion the cookies into 20 large balls. If the dough is very soft, place the dough balls in the fridge for about 15-20 minutes to firm up slightly.
- Using your fingers, flatten each dough ball out to about 3" in diameter. Place a whole marshmallow inside each cookie dough disc and wrap the edges of the dough around the marshmallow, covering most of the marshmallow but leaving some visible on top. Place on prepared baking sheets, marshmallow side up, leaving a few inches to allow for spreading.
- Bake cookies on prepared pans, spaced at least 2 inches apart, for 10 to 13 minutes, or until set at the edges and no longer damp-looking on top. Top each cookie with additional chocolate chips, if desired, and a sprinkle of flaky sea salt.
- Allow cookies to cool on pans for at least 15 minutes before serving. Use caution when biting into the center or breaking apart if the cookies are still warm, as the marshmallow will be hot.
