Prepare your oven for baking the cake:

Bring a large kettle of water to a full rolling boil.

Set one oven rack in the middle of the oven.  Preheat the oven to 350 degrees.  Set a large, flat roasting pan in the middle of the oven.  Fill it with about an inch of the boiling water.  Keep the water at a simmer.

Generously coat the bottom and sides of a 12-cup bundt pan with the softened butter.  Be sure to grease each crevice in the pan.

Pour the caramel sauce in the bottom of the pan.   Set aside.

Make the cake layer:

In the bowl of an electric stand mixer, cream the butter and sugar together until light and fluffy, about 5 minutes.  Beat in the egg.

Meanwhile, in a large bowl, sift together the flour, cocoa powder, cinnamon, cayenne, baking powder, and baking soda.

In a measuring cup, stir the buttermilk and instant espresso powder together.  It won’t dissolve completely, but you want to moisten the espresso powder.

On slow speed, add the dry ingredients to the butter mixture, ⅓ at a time, alternating with the buttermilk mixture.  Don’t over mix the batter.  Set aside.

Make the flan layer.

In a blender, pour in both kinds of milk, cream cheese, eggs, and vanilla paste.  Blend on high for 30 seconds until smooth.

Scoop the cake batter into the prepared bundt pan on top of the caramel layer.  Smooth it out with the back of a spoon.

Next, gently pour the flan mixture into the bundt pan on top of the cake layer.

Lightly butter a piece of foil and tightly cover the top of the bundt pan, butter side down against the cake.

Bring the kettle of water back up to a full rolling boil.