Peanut flour makes delightful low‑carb baked treats like this easy keto peanut butter mug cake. Light, fluffy, and full of peanut flavor, this single‑serve dessert feels indulgent without derailing your macros.
Happy Friday! I had a lovely week. We spent Memorial Day quietly at home—nothing extravagant, just family time. My son and I baked peanut butter chocolate chip cookies while my daughter did crafts, and later my husband took the kids to the park for the afternoon. During that quiet stretch I did some work and treated myself to one of these mug cakes as a snack.
I think peanut flour is one of the best pantry finds for low‑carb baking. I add it to oatmeal, smoothies, pie crusts, layer cakes and now these convenient single‑serve mug cakes (or minute muffins). If you’re unfamiliar with peanut flour, it’s what remains after extracting oil from roasted peanuts. It’s finely milled, high in protein and fiber, and relatively low in fat and carbs compared with many nut flours.
Raw ground peanuts are not the same as peanut flour. Peanut flour is a defatted product and behaves differently in recipes—more like a concentrated flavoring similar to cocoa powder—so it’s best used alongside bulkier ingredients when baking to avoid a dense or crumbly result.
RAW GROUND PEANUTS ≠ PEANUT FLOUR
Peanut flour may appear under names like de‑fatted peanut flour, powdered peanut butter, or branded products such as PB2 (which often contains added salt and sugar). Because it’s so fine, it works best mixed with other ingredients to build structure in cakes, muffins, crackers or breads. For these mug cakes I prefer Sukrin Peanut Flour for its mild, smooth flavor and lighter roast compared with some other brands.
Single‑serve mug cakes are a super‑easy breakfast or snack and have come a long way from early recipes like flax muffins or “muffin in a minute.” One common shortcoming of many mug cakes is texture—they can be rubbery or eggy. I refined this recipe to avoid those pitfalls and deliver a light, cake‑like crumb even in a tiny portion. Each serving is about 2 net carbs.
Tip: Make a master mix by quadrupling the dry ingredients. Store that blend and measure 1/4 cup when you want a single mug cake—add the wet ingredients and microwave. It saves time and keeps results consistent.
Keto Peanut Butter Mug Cake
Ingredients
- 3 tablespoon peanut flour
- 1 tablespoon low carb brown sugar (or preferred sweetener)
- ¼ teaspoon baking powder
- 1 pinch salt
- 1 large egg yolk
- 1 tablespoon mayonnaise*
- 1 teaspoon water
Instructions
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In a microwave‑safe mug, whisk the dry ingredients together with a fork until even.
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Stir in the egg yolk, mayonnaise, and water until fully combined and smooth.
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Microwave on high about 50 seconds (microwave strengths vary). Let the cake rest for 1 minute before enjoying.
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Nutrition (approx.): Calories 195, Fat 17 g, Carbohydrates 4 g, Fiber 2 g, Protein 9 g.
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Chocolate‑peanut butter variation: Use 1 1/2 tablespoons peanut flour and add 1 tablespoon unsweetened cocoa powder (sifted to remove lumps).
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Substitute note: If you prefer not to use mayonnaise, swap in sour cream. If the batter seems dry, add 1 teaspoon of oil along with the sour cream.
Nutrition
Keto Chocolate Mug Cake