Quick Recipe Version (TL;DR)
Quick Ingredients
- 3 tbsp (24 g) all-purpose flour
- 2 tbsp (12 g) unsweetened cocoa powder
- 3 tbsp (38 g) granulated sugar
- 1/8 tsp espresso powder
- 1/4 tsp baking powder
- Pinch of fine salt
- 3 tbsp (45 ml) whole milk
- 2 tbsp (30 ml) neutral oil (canola or vegetable)
- 1/2 tsp vanilla extract
- 2 tbsp (20 g) semisweet chocolate chips, plus 1 tsp for the top
- 1 (10–12 g) square semisweet chocolate (for the molten center)
- To serve: vanilla ice cream or whipped cream
Do This
- 1. In a 12–14 oz microwave-safe mug, whisk flour, cocoa, sugar, espresso powder, baking powder, and salt.
- 2. Whisk in milk, oil, and vanilla until smooth; stir in 2 tbsp chocolate chips.
- 3. Push a chocolate square into the center of the batter and cover it completely.
- 4. Sprinkle 1 tsp chocolate chips on top.
- 5. Microwave on HIGH (1000W) for 70 seconds. (Use 60 seconds for extra-gooey; 80–90 seconds for a more set cake.)
- 6. Rest 1 minute, then top with vanilla ice cream or whipped cream and serve warm.
Why You’ll Love This Recipe
- Rich, fudgy chocolate flavor with a deeper cocoa note from a pinch of espresso powder.
- Molten chocolate center without any fancy technique.
- Made in one mug with pantry basics and minimal cleanup.
- Perfect warm with vanilla ice cream or whipped cream for an easy, crowd-pleasing dessert.
Grocery List
- Produce: None required (optional: berries or mint for garnish)
- Dairy: Whole milk; vanilla ice cream or whipped cream (for serving)
- Pantry: All-purpose flour; unsweetened cocoa powder; granulated sugar; espresso powder; baking powder; fine salt; neutral oil (canola/vegetable); vanilla extract; semisweet chocolate chips; 1 square semisweet chocolate
Full Ingredients
For the mug cake batter (1 mug cake)
- 3 tbsp (24 g) all-purpose flour
- 2 tbsp (12 g) unsweetened cocoa powder
- 3 tbsp (38 g) granulated sugar
- 1/8 tsp espresso powder
- 1/4 tsp baking powder
- 1 pinch fine salt
- 3 tbsp (45 ml) whole milk
- 2 tbsp (30 ml) neutral oil (canola or vegetable)
- 1/2 tsp vanilla extract
- 2 tbsp (20 g) semisweet chocolate chips
For the molten center
- 1 square semisweet chocolate (10–12 g), or 1 heaping tsp chocolate chips (about 6–8 g)
For the top (optional but highly recommended)
- 1 tsp semisweet chocolate chips (for extra gooeyness)
- 1 small scoop (about 1/3 cup / 45 g) vanilla ice cream, or 1/2 cup (30–40 g) whipped cream
Step-by-Step Instructions
Step 1: Choose the right mug
Use a microwave-safe mug that holds at least 12 ounces (350 ml); 14 ounces is even better to prevent overflow. If your mug is smaller, place it on a microwave-safe plate to catch any drips. Lightly wipe the inside with a drop of oil if you want extra-easy cleanup (optional).
Step 2: Whisk the dry ingredients directly in the mug
Add the flour, cocoa powder, sugar, espresso powder, baking powder, and salt to the mug. Whisk well with a fork or small whisk, making sure there are no cocoa lumps hiding along the bottom or sides. This quick mix helps the cake cook evenly and keeps it from tasting floury.
Step 3: Add the wet ingredients and mix until smooth
Pour in the milk, neutral oil, and vanilla extract. Stir thoroughly until you have a smooth, glossy batter and you’ve scraped the bottom corners of the mug. The batter should look like a thick chocolate sauce.
Step 4: Add chocolate chips and create the molten center
Stir in 2 tablespoons (20 g) chocolate chips. Then push 1 square of semisweet chocolate into the center of the batter. Use the spoon to nudge batter over the top so the chocolate is fully covered (this helps it melt into a true molten center instead of scorching).
Step 5: Microwave to fudgy perfection
Sprinkle 1 teaspoon chocolate chips on top (optional). Microwave on HIGH (1000W) for 70 seconds. The cake should look set around the edges but still a little soft and glossy in the center.
If your microwave is more powerful than 1000W, start checking at 60 seconds. If it’s less powerful (700–900W), you may need 80–95 seconds. Avoid overcooking; a mug cake continues to set as it rests, and overcooking can turn it dry or rubbery.
Step 6: Rest, top, and serve warm
Let the mug cake rest for 1 minute so the center thickens into a gooey fudge texture (and so you don’t burn your mouth). Top with vanilla ice cream or whipped cream and serve right away. If you like, add a few extra chocolate chips on top so they melt into the ice cream.
Pro Tips
- For a true molten center: Make sure the center chocolate is fully buried under batter before microwaving.
- Measure flour carefully: Too much flour makes a cakier, drier result. If possible, level your tablespoon or weigh 24 g.
- Don’t skip the salt: A small pinch makes the chocolate taste deeper and less flat.
- Microwave timing is everything: If you want it gooey, err on the lower time and add 5–10 seconds only if needed.
- Mix thoroughly: Scrape the bottom and sides of the mug so you don’t end up with dry pockets of flour or cocoa.
Variations
- Peanut butter lava: Replace the center chocolate square with 1 tsp (5 g) peanut butter (freeze it for 10 minutes first for a more molten pocket).
- Mocha chip: Increase espresso powder to 1/4 tsp and use dark chocolate chips for a bolder coffee-chocolate flavor.
- Peppermint hot cocoa: Replace vanilla extract with 1/4 tsp peppermint extract and use semisweet chips; serve with whipped cream.
Storage & Make-Ahead
This dessert is best eaten immediately while warm and gooey. If you have leftovers, cover the mug and refrigerate for up to 24 hours. Reheat in the microwave on HIGH in 10-second bursts just until warmed through (overheating can make it chewy). Mug cake batter is not ideal for make-ahead (the baking powder starts reacting), but you can pre-measure the dry ingredients into the mug and store at room temperature, covered, for up to 2 days; add wet ingredients right before cooking.
Nutrition (per serving)
Approximate, for 1 mug cake without ice cream or whipped cream: 520 calories, 24 g fat, 74 g carbohydrates, 6 g protein, 45 g sugar, 4 g fiber, 320 mg sodium.
