Description
Want a quick gluten-free snack or single-serve breakfast that actually tastes like cake? This oatmeal mug cake uses only oats (no wheat flour), whisks together in seconds, and finishes in the microwave. The halfway stir is the secret: it prevents rubbery eggs and gives you a light, moist crumb every time.
Ingredients
Scale
- 1 large egg
- 3 Tbsp milk (or dairy-free milk)
- 2 Tbsp pure maple syrup (see notes for alternatives)
- 1 Tbsp neutral oil (canola, vegetable, or melted coconut oil)
- ½ tsp vanilla extract
- ½ cup quick oats (use certified gluten-free oats for GF)
- ½ tsp baking powder
- ¼ tsp ground cinnamon
- pinch (⅛ tsp) salt
- ½ Tbsp mini chocolate chips (optional)
Instructions
- Prep the mug. Use a microwavable mug (10 oz or larger) and spray it lightly with nonstick cooking spray.
- Mix the wet stuff. In the mug, beat the egg with milk, maple syrup, oil, and vanilla using a fork until smooth.
- Add the dry. Stir in the oats, baking powder, cinnamon, and salt until the batter looks even. Hold off on chocolate chips for now if using.
- First cook. Microwave on high for 45 seconds.
- Stir halfway. Take the mug out and whisk the batter briskly — this redistributes the egg so it won’t set into rubbery strings. If you want chips, fold them in now.
- Finish cooking. Microwave again for 45–60 seconds depending on your microwave’s power. The top may still look slightly moist — that’s okay; let it rest a minute and it will finish setting. Do not overcook.
Notes
- Sweetener swaps & notes
- Maple syrup gives the best flavor and moisture.
- Brown sugar or coconut sugar work too but can dry the cake a bit.
- Want less sweet? Try 1–1½ Tbsp sweetener instead.
- I haven’t tested artificial sweeteners here, but a 1:1 monk fruit/erythritol blend should be fine.
- Helpful tips
- Use a 10 oz (or larger) mug — batter rises and will overflow in a small cup.
- Stirring halfway through is crucial. It prevents rubbery eggs and helps produce a uniform, fluffy texture.
- To make two servings, mix separately and microwave each mug on its own.
- Swap the oil for 1 Tbsp creamy peanut butter (or other nut butter) for extra flavor — it will be a bit denser but delish.
- Leftovers? Wrap and chill; reheat briefly in the microwave before eating.
- Variations & add-ins
- Banana option: replace the egg with ½ mashed banana for an egg-free version (results lean toward baked-oat texture).
- Chocolate: add cocoa powder or extra mini chips for a fudgy twist.
- Fruit & nuts: fold in berries, chopped nuts, or a spoonful of nut butter after cooking.
- Bold tip: stir the cake halfway through microwaving — that single step transforms the texture.
Have fun with mix-ins and toppings. Want a recipe card formatted for printing or Pinterest copy + alt text? I can whip that up next.
Nutrition
- Calories: 514kcal
- Sugar: 30g
- Sodium: 378mg
- Fat: 24g
- Saturated Fat: 5g
- Trans Fat: 0.1g
- Carbohydrates: 62g
- Fiber: 5g
- Protein: 13g
- Cholesterol: 166mg