ISO: chocolate cake bottom with flan top

While living in TX along the Mexican Border for over 20 years, I fell in love with a cake that was made in a bundt pan. It was a deep, rich chocolate cake on the bottom and had a flan type custard on the top. Generally it was drizzled with the caramel found on just flan. I asked numerous neighbors and friends and coworkers for a recipe, but, was unsuccessful in obtaining one. I sure would appreciate a recipe if anyone has one or can find one. I've even tried looking online in all Mexican recipe sites and still no luck. Hope someone can help! It's a true chocolate lovers dream!