Combine white chocolate chips and milk in an oversized microwave-safe mug. Microwave for about 40 seconds. Mix with a small whisk until chocolate is completely melted.
Add flour, baking powder, and oil and whisk until batter is smooth.
Using a fork, smash Oreos into the batter until only small chunks of cookie remain.
Cook in microwave for about 1 minute. Let cake cool a few minutes before eating. Cake is best consumed while still warm.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.