How to make
Oven - 360°F (180 °C);
Butter a rectangular 13″ (33 cm) x 9″ (23 cm) form well and flour it slightly (or use round form with 10″ (25 cm) diameter).
1. Beat the flour, cocoa, salt and baking soda in a bowl with a whisk.
2. Beat the eggs, sugar, oil and vanilla with a whisk in a bowl. Add the buttermilk in lots, alternating it with the flour. Beat to a homogeneous mixture and while beating nonstop add the hot water. Pour the mixture into the form.
Bake at 360°F (180 °C) about 30 min. or until your toothpick comes out dry when you poke it in the middle.
Take the baked caked out of the oven and while still hot, make holes in it with the handle of a wooden spoon - 5 holes along the width and 8-9 along the length.
Using a small spoon, fill the holes with Dulce de leche, then spread the entire mixture out along the surface of the cake. Leave to cool completely.
3. Pour the sugar and water in a casserole. Put it on a moderate stove to caramelize. Remove from the stove, add the cream, return to a moderate-high stove, stir energetically until the caramel melts completely - about 1-2 min. Take it off, add 1 tbsp butter, the vanilla, stir to a smooth sauce. Set aside 1/3 cup (85 ml) sauce, leave it aside.
4. Beat the cold cream with a mixer to soft peaks and add 1/3 cup (85 ml) caramel sauce (now thicker) and beat again until homogeneous.
5. Distribute this beaten cream mixture over the cooled cake, smooth out with spatula.
6. Heat the remaining caramel (about 1 2/3 tbsp (25 ml)) if it's hardened in the meantime, then distribute it randomly on top in a thin trickle. Slide a long wooden skewer on top to create the marble effect. Pour the chocolate pearls on randomly.
Let the cake cool fully at room temperature, then store in the fridge.
When serving, cut into large squares or cake slices.
Notes: The easiest way to make buttermilk is to add 1 tbsp citric acid to 1 cup milk. Leave it for 10-15 min.
I made buttermilk from high fat cream. I poured the cream in a deep jar with a cap and while stirring nonstop energetically after about 15-20 min. the buttermilk was released. Butter was the byproduct, which I drained very well.
Source: Home Cooking