Healthy Flourless Chocolate Mug Cake
Yields: 1 mug cake
This dessert is so easy to make, and it tastes so rich and decadent! This mug cake is supremely moist, basically with the same texture as fudgy brownies, and has an irresistible flavor similar to 72% dark chocolate. There’s a reason I make it nearly every single day!
  1. Lightly coat a 1-cup ramekin with nonstick cooking spray.
  2. In a small bowl, whisk together the oat flour, cocoa powder, baking powder, and salt. In a separate bowl, stir together the butter, Greek yogurt, and milk.* Stir in the vanilla extract and vanilla stevia. Gradually mix in the flour mixture, about 1 tablespoon at a time, until just incorporated. If using, gently fold in ¾ teaspoon of chocolate chips.
  3. Spread the batter into the prepared ramekin, and gently press the remaining chocolate chips on top (if using). Microwave on 30% POWER for 2 minutes 45 seconds (2:40). Let the mug cake cool for at least 4 minutes to allow the center to finish cooking through.
Notes: To see how to make your own oat flour, see my tutorial here!

White whole wheat flour, whole wheat pastry flour, regular whole wheat flour, or all-purpose flour may be substituted for the oat flour. Most store-bought gluten-free flour blends (like this one!) will also work, if measured like this. Do not substitute coconut flour.

It’s very important to measure the oat flour and cocoa powder correctly, using this method or a kitchen scale. (← That's the one I own and love!) Too much of either will make the mug cake dry (and too much cocoa powder will make the mug cake taste bitter). If your batter is too dry, add additional milk ½ teaspoon at a time until the batter resembles the texture of thick muffin batter.

I don’t recommend substituting Dutched or special dark cocoa powder. Those will taste muted and bland compared to regular unsweetened cocoa powder.

Any milk may be substituted in place of the nonfat milk.

I highly recommend using the vanilla stevia! It's one of my favorite ingredients, and you'll use it in all of these recipes of mine, too. I buy mine online here because that's the cheapest price I've found. Other sweeteners may be substituted in place of the vanilla stevia, but you may need to adjust the amount of oat flour or milk depending on the type of sweetener that you use. You’ll need the equivalent of 2-3 tablespoons of granulated sugar in the mug cake.

As written, this mug cake tastes similar to 72% dark chocolate. For a sweeter taste, increase the amount of vanilla stevia by up to an additional ¼ teaspoon.

If the Greek yogurt and milk are cold, they will immediately re-solidify the melted butter or melted coconut oil. If this happens, microwave on HIGH for 6-8 seconds or until the butter/coconut oil re-melts; then proceed with the rest of the instructions.

It’s VERY important to microwave the mug cake on 30% power. This is set differently depending on the brand of microwave that you own. If microwaved on HIGH (full power) for a shorter time, the cake will be gummy, and the top may be overdone while the insides stay raw.

Microwave times may vary, depending on the wattage of your microwave oven. I used a 1000-watt microwave. If using a 1100-watt microwave, I recommend using 20% power instead. The mug cake will take longer to cook at 20% power. (I’m not sure how long since I don’t own one!)

To bake the mug cake in a regular oven, bake at 350°F until the top feels firm to the touch and a toothpick inserted into the center comes out clean. I haven’t cooked the mug cake this way myself and can’t guarantee how long it will take, but check for doneness after about 10-12 minutes to start.

{gluten-free, clean eating, low fat, low sugar, higher protein}
Recipe by Amy's Healthy Baking at