Name: Microwave Sponge Cake (Egg-free, Stays Soft for 3 days)
Prep time: 10 min
Cook time: 8 min
Total time: 18 min
Ingredients: 6 Tablespoons salted butter (at room temperature); ½ cup white granulated sugar; ¼ cup plain yogurt ((see note 1)); 1 cup full-fat milk; 1 ⅓ cups all-purpose flour (plain flour); ¼ teaspoon salt ((½ teaspoon if using unsalted butter)); 2 level teaspoons baking powder; 1 teaspoon vanilla extract

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My easy to make Microwave sponge cake bakes in under 8 minutes, is egg-free, and stays soft for 4 days! Celebrate anytime with this quick bake which has amazing flavour and texture.

Visual Instructions

These visual instructions help you see the process. You can also find the full printable recipe with instructions and ingredients at the end of the post.

Use a whisk or handheld beater to beat the butter. Add the sugar and vanilla extract and beat until well incorporated.
Pour in the yogurt and mix to combine.

Sift in the flour and baking powder and mix until just combined.
Add the milk and use a whisk or handheld beater to beat for one minute.

Pour the mixture into a microwave-safe dish lined with parchment paper. Microwave on high for 6-8 minutes. Check for doneness by inserting a toothpick in the center; if it comes out clean, the cake is ready. If not, continue baking until done.
Allow the cake to cool in the container for 10 minutes, then transfer to a plate to cool completely before decorating.

Tips for baking in a microwave

Use microwave-safe containers like glass, silicone, plastic, or ceramic (avoid metal). Silicone creates a denser cake, while glass gives a fluffier texture. A rounded container ensures even cooking.

Bake at full power for 8-10 minutes, checking every 4 minutes with a toothpick. If it comes out clean, the cake is done. If not, bake in 1-minute increments until fully cooked. The cake should be firm and pull away from the sides.

Baking time varies by microwave wattage (this recipe is based on a 1000-watt microwave). Adjust time accordingly.

The cake continues to bake for 2 minutes after being removed from the microwave so avoid overbaking

Toppings and Frosting Ideas

These can be as simple or elaborate as you like, depending on the occasion or your mood. Here are some of the best toppings I’ve used in my recipes:

Use your favorite frosting to decorate the cake, whether it’s a simple dusting of powdered sugar or a rich buttercream frosting, like the one I used for my Condensed Milk Lemon Cake.
Top with a light dusting of powdered sugar.
Frost with piped or spread chocolate buttercream.
Try my delicious 3-ingredient stabilized whipped cream frosting (without gelatin) and top with seasonal fruit.
Cover with a smooth chocolate ganache.