1. Heat the oven to 150°C. Spray an ovenproof ceramic or glass dish that will look nice on the table with a light coating of cooking oil spray. I use a 30 cm x 20 cm oval, but you’ll just need to choose one where the batter sits half to two-thirds up the side to prevent baking overspill.
2. Hand whisk the boiling water, chocolate, cocoa, and coffee in a wide bowl until the chocolate has melted. Set aside to cool while you get the other bits ready.
3. Swizzle the flour, sugar, baking powder, bicarb and salt together and set aside with a sieve.
4. Hand-whisk the milk, egg, and oil in the chocolate mix until well emulsified.
5. Sift over the dry ingredients and whisk well until no floury streaks remain—the batter will be loose and goosey.
6. Scrape into the prepared dish and bake for 35-45 minutes until springy to touch (or internal 90°C). Do not worry if you overbake, as the soak will alleviate any dryness.
7. You need hot cake to meet hot soak so while the cake bakes, heat up all the soak ingredients slowly over a low heat, stirring often to encourage the chocolate to melt.
8. When the cake has been baked, place it on a cooling rack, take a fork and poke deep holes over the entire cake, dragging your fork a little to create a deep cleft to allow the soak to well, soak!
9. Start pouring the soak over, being mindful to cover the entire surface evenly—don’t neglect the sides. If any soak starts to pool, re-fork to allow the soak to sink in.
10. Once all the soak has been taken up, allow the tres leches to cool completely at room temperature.
11. Once cool, whip the cream with a pinch of salt to flexible, billowy peaks and pile over the surface of the cooled cake. Use the back of the spoon to kick up some texture over the top.
12. Finely grate the extra chocolate over the top like a dark, delicious snowdrift.
ADAPTRIX: I haven’t tried it, but my keen baking instincts believe that the milk in here could be subbed for non-dairy alternatives. I have even spied a sweetened condensed oat milk! The recipe can be easily halved or quartered for solo tres leches. Just ensure the baking vessel follows the batter level recommendation from 1.