1. Preheat oven to 450 degrees Fahrenheit (230 degrees Celsius).
2. In a medium-sized pot, melt butter and chocolate. Stir in caramel cream until combined; remove from heat. Add brown sugar, eggs, and yolks; stir to combine. Slowly sprinkle in flour, mixing gently to combine and to remove any lumps.
3. Spray seven individual ramekins with cooking spray and divide mixture evenly among them. Place ramekins on a baking sheet and bake for 13 minutes. Remove from oven and invert one cake onto a plate; if it comes out in one piece, it’s ready. If not, return to ramekin and return the baking sheet to the oven. Continue checking the cakes every minute, being careful not to overbake, as the center should stay soft and gooey. Serve warm.