Steps
1. In a small bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
2. Add milk, vegetable oil, and yogurt to the dry ingredients. Mix until smooth and combined.
3. Fold in chocolate chips gently.
4. Grease a microwave-safe mug or small bowl lightly with oil.
5. Pour the batter into the prepared container, smoothing the top.
6. Microwave on high for 90 seconds. Check for doneness; if not set, microwave in additional 10-second increments.
7. Let cool for 2 minutes before enjoying your spongy cookie cake.