In a large bowl whisk together the flour, cocoa powder, baking soda and salt.

In another bowl mix sugar with eggs and oil until combined. Mix in buttermilk and vanilla extract. Incorporate flour mixture until well combined. Add hot water and mix to combine. The batter will have a runny consistency.

Pour the batter into the prepared pan.

Bake for about 30 minutes or until a toothpick inserted into the center comes out clean or with few crumbs attached.

Remove the cake from the oven and while still warm poke the cake with the handle of a wooden spoon.

Fill the holes with caramel sweetened condensed milk (dulce de leche). Refrigerate for about 1 hour.

Remove the pan from the heat and add the cream. It will bubble a little bit.

Cook for about 1 minute stirring constantly with a wooden spoon until smooth.

Remove from heat and add vanilla, butter and salt. Stir well until smooth. Cool to room temperature.

Whip chilled cream until stiff peaks form. Slightly incorporate 1/3 cup (80g) of caramel sauce.

Spread evenly over the top of the cake.

Melt the remaining caramel and drizzle on top. Use a toothpick to create swirl.

Refrigerate the cake until ready to serve.

Decorate with mini semisweet chocolate chips or grated chocolate.