The "impossible cake" layers chocolate cake and flan that magically swap during baking. This family-friendly dessert is an ingenious, show-stopping treat for celebrations and special occasions.
Preheat oven to 350°F. Grease a 10-inch bundt pan and set aside.
Spread sugar evenly in a saucepan over medium heat; cook, stirring constantly, until melted and deep amber. Quickly pour into prepared pan, tilting to coat the bottom before caramel cools.
In a blender, combine sweetened condensed milk, evaporated milk, cream cheese, eggs, and vanilla extract. Blend until fully smooth and set aside.
In a bowl, mix cake mix, cocoa powder, vegetable oil, water, and two eggs. Whisk until the batter is just combined without overmixing.
Pour the chocolate cake batter over the cooled caramel in the pan. Carefully pour the flan mixture over the cake batter. The layers will invert during baking.
Cover pan tightly with foil. Place bundt pan in a larger roasting pan and fill the roasting pan with hot water until it reaches halfway up the sides. Bake for about 80–90 minutes until a tester comes out clean from the flan center.
Remove cake from the water bath and let cool to room temperature (at least 1 hour). Then refrigerate for 2–3 hours until fully set. Invert onto a plate so the caramel is on top. Slice and serve chilled.