Chocolate zucchini mug cake is a quick dessert treat to make when your sweet tooth strikes. Filled with simple baking ingredients and shredded zucchini, this fluffy, rich mug cake is ready in only 60 seconds in the microwave.
What is a mug cake? A mug cake is a single serving of cake that's cooked in a coffee mug in the microwave. This particular mug cake is similar to my chocolate zucchini snack cake recipe - it's moist and fluffy, with rich chocolate flavor.
Chocolate zucchini mug cake is made with pantry staples like flour, oil, sugar, baking powder, and milk. Shredded zucchini adds structure and moisture, meaning we can cut back slightly on other ingredients, like oil and flour. Cocoa powder and chocolate chips add rich chocolate flavor to this mug cake - it's perfect for chocolate lovers.
Make yourself a mug cake next time that sweet tooth strikes! This mug cake makes one single serving, perfect for when you don't want leftovers lying around. For a chocolate-free mug cake, try my apple spice zucchini mug cake.
Ingredients and substitutions
- Zucchini - I recommend using finely grated zucchini, which has a less noticeable texture in your finished cake. You'll also want to squeeze out as much moisture as you can from your zucchini, otherwise your cake can turn out gummy.
- Vegetable oil - Adds moisture to your cake. Can be substituted with melted butter if desired.
- Granulated sugar - Adds sweetness and moisture to your cake.
- Milk - Adds moisture to your cake. Can be any milk you have on hand, like cow's milk, almond milk, or oat milk.
- Vanilla extract - Adds depth of flavor to your mug cake. Can be omitted without affecting the texture of the cake.
- All-purpose flour - Adds structure to your cake. I haven't tested this recipe with anything other than all-purpose flour, so I can't say for sure how it would turn out with other types of flour.
- Baking powder - Adds lift to your cake. Cannot be substituted with baking soda, the two are not interchangeable.
- Natural cocoa powder - Gives your cake its chocolate flavor.
- Chocolate chips - Chocolate chips turn into tiny melted chocolate spots throughout your mug cake. I used semi-sweet chocolate chips, but these can be substituted with any baking chips you have on hand. Peanut butter chips, white chocolate chips, or milk chocolate chips all work.
I recommend making your mug cake in a 12 ounce coffee mug. A tall, thin, standard coffee mug works well. The tall cylindrical shape of a standard mug helps your cake rise more.
This cake takes up about 8 ounces of space when cooked (and puffs up a little more in the microwave), so using a smaller mug may result in some cake batter spilling over the edges as it cooks.
How to make a moist mug cake
The moisture in this mug cake comes from your wet ingredients: shredded zucchini, oil, milk, and granulated sugar. Omitting or substituting these ingredients can cause your cake to turn out dry.
Take care not to overcook your cake - cooking for too long will result in a dry cake as well.
If you've never made a mug cake before, take a look at your cake after 50 seconds, then cook in 10 second increments after that until your cake no longer looks wet on the top.
Optional mix-ins and toppings
Want to add extra to your chocolate zucchini mug cake? Here are a few ideas to get you started.
Mix-ins (add 1-2 tablespoons per mug cake):
- White chocolate chips
- Peanut butter chips
- Chopped walnuts
- Milk chocolate chips
- Whipped cream
- Buttercream frosting
- Peanut butter
- A scoop of vanilla ice cream
- Caramel sauce
- Hot fudge
Chocolate Zucchini Mug Cake
- 2 tablespoons finely grated zucchini, liquid squeezed out
- 2 tablespoons granulated sugar
- 1 tablespoon vegetable oil, or melted butter
- 1 tablespoon milk
- ¼ teaspoon vanilla extract
- 3 tablespoons all-purpose flour
- 1 tablespoon natural cocoa powder
- ½ teaspoon baking powder
- pinch salt
- 1 tablespoon chocolate chips
- In a 12 ounce coffee mug, add grated zucchini (with the liquid squeezed out first), sugar, oil, milk, and vanilla extract. Stir to combine.
- Add dry ingredients: flour, cocoa powder, baking powder, and salt. Stir until just combined. Add chocolate chips and stir until incorporated.
- Microwave for 50 seconds, check your cake, then continue cooking in 10 second increments until the top of the cake no longer looks wet. Cooking time depends entirely on the wattage of your microwave and will vary model to model (we used a 1000 watt microwave oven).
- Allow cake to cool for 5 minutes before enjoying - it will be very hot straight from the microwave!
- a pinch = about 1/16 of a teaspoon
- Chocolate chips can be substituted with your favorite baking chips, like peanut butter chips or white chocolate chips.
- If using a smaller mug, place a paper towel under your mug before microwaving to catch any potential batter overflow. Cake will rise while cooking, and will take up about 8 ounces of space once cooked.