Copy and paste from the following website.
It has pictures step by step and also useful tips for making the lava part.
用料
| Flour | 1/4 cup |
| Granulated sugar | 1/4 cup |
| Unsweetened cocoa powder | 2 tbsp |
| Baking powder | 1/2 tsp |
| Salt | some |
| Melted butter | 3 tbsp |
| Milk | 3 tbsp |
| Egg | 1 |
| Vanilla extract | 1/2 tsp |
| Water | 1 tbsp |
Microwave Molten Chocolate Mug cake的做法
In a 2-cup capacity microwave-safe mug* (see note), whisk together with a fork, the flour, sugar, cocoa powder, baking powder and salt until well combined.
Add in the melted butter, milk, egg and vanilla. Whisk well to combine, making sure to mix in the flour mixture in the bottom.
Place the chocolate pieces in the center of the mug. Do not push down; it will sink as it bakes.
Drizzle the tablespoon of water right on top of the batter.
Cook in microwave on full power for 1 minute and 20 seconds to 2 minutes (1 minute and 25 seconds is my magic number), or until the cake rises to the top, the edges look set but the center looks ever-so-slighly wet and shiny but not raw, and sticks slightly to the finger when touched. Do NOT overbake to ensure that saucy, molten-y interior. If the center still looks raw then give it another 5 to 10 seconds. The cake will fall after it comes out of the microwave.
Let it cool for about 5 minutes so you don't burn your tongue, but the waiting also help thicken the sauce in the bottom.
小贴士
* A short mug with a wide mouth works best for this recipe. If not available, a small bowl could be used instead. To know if your mug/or bowl is the right size, pour 2 cups of water in it and this should fill it to the top.
* If trying to avoid the microwave, this cake could be baked in a 400F/200C oven for 10 to 15 minutes.
