Select a sturdy mug with a capacity of 10–12 oz. (300–360 ml).

Place the butter in the mug and microwave it for about 30 seconds or until completely melted. Swirl it around to coat the mug if desired.

Whisk in the milk until fully blended with the melted butter. Gradually stir in the sugar, vanilla extract, and almond extract if using. Add the baking powder and a small pinch of salt, ensuring a smooth mixture.

Slowly incorporate the flour into the wet ingredients. Stir until no lumps remain. If you’d like to add sprinkles or other mix-ins, fold them in at this stage. For a festive touch, sprinkle additional decorations on top of the batter.

Microwave the mug cake for 90 to 120 seconds. During this time, it will rise significantly. Once the cake sets and looks fluffy, check the bottom for any remaining liquid. If necessary, heat in 20-second intervals until the texture meets your preference.

While the cake cools slightly, prepare the frosting. Using a small bowl, cream the softened butter until smooth. Gradually mix in the powdered sugar, adding milk as needed for a creamy consistency. For added flavor, include a touch of vanilla extract for a classic frosting or cocoa powder for a chocolatey twist. Adjust sweetness as desired.

Once the mug cake has cooled to room temperature, generously spread the frosting on top. Finish with a scattering of sprinkles for extra charm.

Enjoy your delightful vanilla mug cake, perfect for any occasion!