Steps
1. Preheat oven to 350°F (180°C) and grease a ramekin.
2. In a bowl, mix flour, cocoa powder, sugar, and salt.
3. Stir in melted butter, egg, and vanilla until well combined.
4. Pour half of the batter into the ramekin, add chocolate chips, then top with the rest of the batter.
5. Bake for 12-15 minutes until the edges are set but the center is still soft.
6. Let cool for a minute, then invert onto a plate and serve warm.