Impossible Cake

Preheat oven to 350 degrees F (175 degrees C).

Grease the base and sides of a 10-inch fluted tube pan.

Dust lightly with flour; tap to remove excess.

Fill a shallow baking pan with enough water to come 1/3 of the way up the sides of the tube pan.

Place water bath in the oven to warm up while it is preheating.

Pour caramel sauce into a microwave-safe bowl.

Microwave until warm and pourable, about 1 minute.

Pour into the prepared tube pan, covering the base completely.

Mix flour, cocoa powder, baking soda, and baking powder together in a bowl.

Beat 1/2 cup plus 2 1/2 tablespoons butter in a bowl with an electric mixer until smooth.

Add sugar; beat until light and fluffy.

Beat in 1 egg and coffee.

Alternate adding flour mixture and milk, mixing well between additions.

Pour cake batter evenly over caramel in the tube pan.

Combine evaporated milk, condensed milk, 4 eggs, and vanilla extract in the bowl of a food processor; blend until smooth.

Pour over cake batter through a fine sieve.

Bake in the water bath in the preheated oven until a toothpick inserted into the chocolate cake comes out clean, about 1 hour.

Let cake cool, about 1 hour.

Carefully run a thin knife around the edges to loosen the cake, cover with a serving plate, and flip onto the plate.