Preheat the oven to 170°C and prepare your baking mold by lining it with parchment paper. Sift together the cake flour, baking powder, cocoa powder, coffee powder, and salt, ensuring the mixture is even and free of lumps. In a separate mixing bowl, whisk the eggs just until smooth, then add the sugar. Continue whisking until the sugar dissolves and the mixture appears slightly pale.

Gently fold in the sifted dry ingredients, whisking only until everything is fully incorporated. Pour in the melted butter and mix again until the batter becomes glossy and smooth. Add the evaporated milk, whisking to form a uniform, pourable batter. Transfer the mixture into the prepared mold, tapping it lightly on the counter a few times to expel any trapped air bubbles. Bake at 170°C for about 25 minutes, or until the cake feels set when lightly touched. Remove from the oven and set aside to cool while you prepare the topping.

For the caramel toffee topping, place the sugar in a pot over medium heat and allow it to melt slowly, stirring occasionally until it forms a smooth amber syrup. Add the butter and stir until it dissolves completely into the caramel. Pour in the evaporated milk along with the coffee powder, stirring well to achieve a creamy consistency. Incorporate the honey, then turn off the heat. Continue stirring as you add the vanilla extract and cake flour, mixing thoroughly until no streaks remain. Fold in the cashew nuts and almonds, ensuring they are evenly coated in the toffee mixture.

Spread the warm caramel-nut topping evenly over the surface of the partially cooled cake using a spatula. Return the cake to the oven and bake again at 200°C for 15 minutes, allowing the topping to bubble and set into a rich, glossy layer. Remove from the oven and let the cake cool completely for at least 2 hours to allow the topping to firm up.

Once cooled, slice and serve. Enjoy the harmonious blend of soft chocolate cake and crisp, buttery toffee nuts in every bite.