Sugar Free Flourless High Protein Brownie Mug Cake
If you’ve ever wanted a warm, fudgy brownie without making an entire pan, this Sugar Free Flourless High Protein Brownie Mug Cake is the perfect solution. Made with simple ingredients like Greek yogurt, cacao powder, an egg yolk, and dark chocolate, this protein mug brownie is ready in about one minute in the microwave. A satisfying warm brownie and with 8 grams of protein!
Why You’ll Love This High Protein Brownie
Unlike many protein mug cake recipes that rely on chocolate protein powder or almond flour, this protein mug cake recipe has a rich chocolate flavor without any whey protein powder, flour, cottage cheese or added sugar.
The result is a soft, gooey center with plenty of chocolate flavor to satisfy a chocolate craving for a sweet tooth while keeping carbs low and with 8 grams of protein.
- Ready in about 1 minute using the microwave brownie instructions.
- Just a handful of simple ingredients.
- Flourless, gluten free, sugar free, and low carb.
- Naturally high in protein thanks to Greek yogurt and an egg yolk.
- Rich chocolate flavor with a fudgy brownie batter texture.
- No almond flour, coconut flour, or protein powder needed.
- Perfect when you’re craving a sweet treat but don’t want leftovers tempting you.
- Also includes oven and air fryer instructions.
What Makes This Mug Brownie Different?
Years ago I shared my Best Sugar Free Gluten Free Low Carb Keto Mug Brownie in my cookbook, The 30-Day Sugar Elimination Diet. That recipe makes two servings and uses sunflower seed flour along with a few more pantry ingredients.
After hearing from so many readers who wanted something even easier with less dry ingredients, I started experimenting with a single-serve brownie recipe using fewer ingredients. After several rounds of testing, I discovered that using just an egg yolk instead of a whole egg created the rich, fudgy brownie texture I was looking for.
The result is this Sugar Free Flourless High Protein Brownie Mug Cake. It’s made with minimal ingredients, has an incredibly gooey center, and it’s a quick fix to satisfy a chocolate craving in minutes.
Ingredient Notes
You only need a few pantry staples:
- Egg yolk creates an incredibly rich, fudgy brownie instead of a rubbery texture.
- Plain Greek yogurt adds moisture, protein, and keeps the brownie soft.
- Unsweetened cacao powder provides deep chocolate flavor or unsweetened cocoa powder
- Vanilla extract enhances the chocolate.
- Vanilla liquid stevia sweetens without sugar
- Sea salt balances the sweetness.
- 85% dark chocolate creates delicious pockets of melted chocolate throughout the brownie.
Recipe Tips for 1 Minute Protein Brownie
- Microwave strengths vary, so begin checking around 45 seconds.
- The top should look set while the center stays slightly soft.
- Allow the brownie to rest for 2 to 3 minutes after cooking. It continues cooking as it cools, giving you the perfect gooey brownie texture.
- Overcooking is the biggest reason mug cakes become dry or rubbery.
Easy Ingredient Swaps
Need to customize this recipe? Here are a few simple substitutions.
Dairy-Free
Replace the Greek yogurt with your favorite unsweetened dairy-free yogurt. Unsweetened coconut yogurt or almond milk yogurt both work well. Keep in mind the protein content will be lower.
Sweetener
Any liquid sugar-free sweetener can be used, including liquid monk fruit or liquid allulose. Adjust to your preferred sweetness.
Cocoa Powder
Natural cocoa powder can be substituted for cacao powder if that’s what you have on hand. Cacao powder simply provides a slightly richer chocolate flavor.
Chocolate
The chopped 85% dark chocolate or higher is optional, but highly recommended if you love pockets of melted chocolate. You can also use your favorite sugar-free chocolate bar.
Frequently Asked Questions
Can I make this ahead of time?
This recipe is best enjoyed warm immediately after cooking while the center is still soft and fudgy.
Why only use the egg yolk?
The yolk adds richness and helps create a moist, fudgy brownie. Using a whole egg can make small mug cakes slightly more cake-like and less dense.
Can I use protein powder?
I don’t recommend it for this recipe. Protein powder absorbs a lot of moisture and changes the texture. This recipe gets its protein naturally from the Greek yogurt and egg yolk.
Can I bake this instead of microwaving?
Yes! I’ve included microwave, oven, and air fryer instructions so you can choose whichever cooking method you prefer.
More Single-Serve Desserts You’ll Love
If you love easy desserts and chocolate-y treats made with wholesome ingredients that are single-serve recipes, be sure to check out these favorites:
- Lemon Mug Cake
- Chocolate Soufflé Cake
- Peanut Butter Cheesecake Mousse
- Strawberry Cheesecake Jars
- Angel Food Cake Parfaits
Sugar Free Chocolate Protein Mug Cake
Sugar Free Flourless High Protein Brownie Mug Cake
Ingredients
- 1 large egg yolk
- 2 tbsp 2% plain Greek yogurt
- 2 tbsp cacao powder
- 1/2 tsp vanilla extract
- 1/2 tsp vanilla liquid stevia
- pinch sea salt
Optional
- 1 tbsp 85% dark chocolate or 1 square, chopped
Instructions
Microwave Instructions
- Lightly grease an 8-ounce microwave-safe ramekin or mug.
- Whisk the egg yolk and Greek yogurt until smooth.
- Stir in the cacao powder, vanilla, vanilla stevia, and sea salt until well combined.
- Fold in the chopped dark chocolate, if using.
- Microwave for 45–60 seconds. The edges should be set while the center remains slightly soft.
- Let the brownie rest for 2–3 minutes before enjoying. It will continue to set as it cools.
Oven Instructions
- Preheat the oven to 350°F .
- Prepare the batter as directed above.
- Pour into a lightly greased 8-ounce oven-safe ramekin.
- Bake for 8–10 minutes, until the edges are set and the center is still slightly soft.
- Let cool for 5 minutes before serving.
Air Fryer Instructions
- Preheat the air fryer to 325°F.
- Grease an 8-ounce oven-safe ramekin.
- Prepare the batter and pour it into the ramekin.
- Air fry for 7–9 minutes, until the edges are set but the center is still slightly soft.
- Let it rest for 5 minutes before serving. It will continue to set and become fudgy as it cools.
Notes
- The egg yolk creates a richer, more brownie-like texture than a whole egg.
- Don’t overbake. This dessert is best when the center is still fudgy.
Nutrition
About Brenda
Brenda Bennett is a certified Nutritional Therapy Practitioner, certified Sugar Detox Coach, certified Keto Coach, and certified Life Coach. She has been Sugar Free & refined-carb free for 20 years and is the author of four cookbooks: Sugar-Free Mom, Naturally Keto, The 30-Day Sugar Elimination Diet, and her newest release, Good, Better, Best (2025). Her work focuses on helping women detox from sugar, eliminate cravings, balance blood sugar, and lose weight while enjoying delicious, nutrient-dense whole foods. Brenda is also the creator of the Midlife Macro™ Method and the weekly Midlife Macro Meal Plans™, designed specifically for women in perimenopause and menopause who want simple, high-protein, low-carb meals to support hormones, metabolism, and long-term health.She is the founder of the Sugar Free Fresh Start course and the Sugar Free Mom Tribe membership.
