Method
Butter melting: Place the butter in a microwave-safe mug. Microwave for 10-20 seconds, or until melted.
Wet ingredient mixing: Add the egg to the mug and whisk thoroughly with the melted butter. Stir in the milk and vanilla extract until fully combined.
Dry ingredient preparation: In a small bowl, whisk together the coconut flour, sweetener, baking powder, and a pinch of salt. Ensure there are no lumps.
Batter combining: Add the dry ingredients to the mug. Mix until a smooth, uniform batter forms.
Microwaving: Microwave on high for 60-80 seconds, depending on your microwave's wattage. The cake is done when it has risen and the center is just set. Do not overcook to maintain a moist texture.
Cooling and serving: Let the cake cool for 1-2 minutes. Enjoy it directly from the mug or turn it out onto a plate.
Topping suggestions: Top with chopped nuts, fresh berries, keto-friendly ice cream, or whipped cream as desired.
Refrigerate: Store leftover mug cake covered in the refrigerator for up to 2 days. Reheat in the microwave for 15-20 seconds before serving.
Freezing: Not recommended for freezing as the texture will become dense and lose its fluffy quality when thawed.