Black Sesame Mug Cake (Paleo, Gluten Free)

Start-to-finish, this Asian-inspired black sesame mug cake can be made and cooked in your microwave in less than five minutes! Plus, it makes a spooky single serve gluten-free sponge cake for Halloween!

A spooky Halloween mug cake!

Yes, I’ve definitely jumped on the mug cake craze. After coming up with pumpkin, apple, matcha, vanilla, and chocolate mug cake recipes, I decided to tackle a black sesame cake for Halloween—both for the ominous color and the fantastic taste. The resulting black crumb and texture remind me of the springy chiffon cakes my mom loves to bake—but this single serve cake can be whipped up in a fraction of the time!

What is Japanese black sesame paste?

The key ingredient in this black sesame mug cake is Japanese black sesame paste, also known as kuro neri goma.  It’s typically made by roasting unhulled black sesame seeds and then grinding them multiple times through a ceramic grinder to form a smooth and silky black sauce. Flavor-wise, Japanese black sesame paste is deeply nutty and earthy, with only a subtle bitterness.

Where do you buy Japanese black sesame paste?

You can buy black sesame paste online or at your local Japanese market. It normally comes packed in small glass jars or in upright plastic bags with pouring spouts—you can find them stocked near the sesame seeds at the store. Read the label to make sure the only ingredient listed is black sesame seeds.

Before you use black sesame paste, you’ll need to stir it well because the oil can separate, just like other natural seed and nut butters. After opening the jar, keep it in the fridge for up to a month.

What if you can’t find black sesame paste?

If you can’t find Japanese black sesame paste, you can substitute black tahini but the flavor won’t be quite the same. Black tahini has a less pronounced nutty flavor because the seeds aren’t roasted (or only mildly roasted); as a result, it may taste more bitter. On the upside, black tahini is quite a bit cheaper! Also, you can make your own black sesame paste at home but it may not turn out as smooth unless you have a powerful blender or food processor.

Can you make this mug cake in the oven?

Yes, but the resulting cake will taste eggier and the crumb won’t be as springy. (Plus, it’ll take a lot longer!) With that in mind, here are the instructions: Pour the batter into an oven-safe 6-ounce ramekin and bake it in a 350°F oven or toaster oven for 18-20 minutes or a 325°F air fryer for 13-15 minutes. The tiny single serve cake is done when a toothpick inserted in the middle comes out clean. (If you’re worried about cooking food in the microwave, here’s an article from Harvard Medical School that addresses microwave cooking and nutrition.)

Can you make an egg-free or vegan mug cake?

Unfortunately, I tried making this recipe with a couple of different egg substitutes—Bob’s Red Mill egg replacer and a flax egg—and both produced a dense, gooey cake rather than a light and fluffy one. I really don’t think this recipe works well without an actual egg because it’s essential for the structure of the mug cake.

Other Ingredient Substitutions?

As I mentioned in my Matcha Mug Cake recipe, baking is a science that requires precise measurements, so if I haven’t specifically mentioned a potential substitution, it’s because I don’t know if it will work. If you make a substitution and find success, please share your results in the comments so others can benefit from your knowledge!

How to make a black sesame mug cake

In a liquid measuring cup or small bowl, add the almond flour, baking soda, and salt. Whisk the dry ingredient mixture until uniform.

Add the black sesame paste, maple syrup, avocado oil, vanilla extract, and egg. Whisk the cake batter until smooth.

If you want the mug cake to look pretty, scrape the batter with a silicone spatula into a microwave-safe mug (6- to 8-ounce size is optimal). However, you can totally microwave the cake in the glass liquid measuring cup if you want to cut down on dishes to wash.

Place the mug in the center of your microwave (it will rise more evenly in that spot), and cook on high power for 1-2 minutes.

The black sesame mug cake is finished cooking when it puffs up and a toothpick inserted into the center comes out clean. Don’t worry if your cake looks lopsided or collapses—it will still taste great!

I have a 900 watt microwave and my mug cakes are done in 90 seconds. Adjust the cooking time depending on the strength of your microwave—decrease the time if you have a higher wattage microwave and increase it if you have a less powerful microwave.

Let the cake cool for a few minutes and top with candied eyeballs, if desired.

It’s a perfectly splendid way to teat yourself and your loved ones to a quick, sweet and spooky dessert!

Craving more spooky Halloween treats?

I got you covered! Here are some of my faves:

• Yummy Mummies (a.k.a. Halloweenies)
• Bloody Eyeballs (Blueberries Stuffed in Longans in Berry Sauce)
• Matcha Mug Cake (and decorate it like Frankenstein’s monster!)