Preheat oven at 350F/180C.
In a mixing bowl, whisk together all the dry ingredients (Cocoa Powder, Sugar, Flour, Baking Powder and Salt)
In another mixing bowl, whisk together all the wet ingredients (Eggs, Sour Cream, Oil and Vanilla Extract)
Then, combine the wet mixture to the dry mixture. Whisk until smooth.
Place your Medium Round Mold Flexipan® Tray on the top of your perforated baking sheet.
Pour your preparation in the Flexipan and refrigerate for 30 minutes.
Take your tray out of the fridge and gently place the Speculoos Cookies on the top of the batter.
Bake for 23 minutes at 350F/180C. (Every oven heats differently, monitor your chocolate cake from 20min)
Once your chocolate cake is out of the oven, let it cool down for about 10min. Then, Unmold, Serve and Enjoy! Bon Appétit!