Preheat the oven to 375º Fahrenheit / 190º Celsius and line a baking tray with parchment paper. Grease a 9" springform pan with butter or cooking spray.
In a large mixing bowl, add flour, sugar, cacao powder and baking powder. Combine all together with a whisk. Make a well in the middle and pour milk. Add melted butter, vanilla extract and eggs. Mix with a wooden spoon just until combined.
Pour the batter into the springform and spread evenly. Top with Oreos. Press gently to make Oreo stick to the batter.
Place springform on the baking tray and bake in the oven for 55 minutes or until a skewer comes out clean from the cake.
Melt one cup of chocolate chips and 1/2 cup of heavy cream in a microwave safe bowl for 30 seconds. Stir well and microwave in 10 second intervals until the mixture is smooth and silky. Drizzle over the cake.
Remove from the oven and let it completely cool down before serving.
*Spoon the flour into the measuring cup lightly and use a knife to level it off. If you pack it in the cake may be dry.The calories shown are based on the cake being cut into 8 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**