Preheat your oven to 350°F (180°C) and make sure to turn off the fan if your oven has one, this helps the cake bake more evenly.

Line an 8-inch cake pan with baking paper so your cake comes out smoothly without sticking or breaking apart.

In a large bowl, whisk together the flour, cocoa powder, baking powder, baking soda, espresso powder, salt, and both sugars until everything is well combined and fluffy.

Next, add the eggs, milk, water, vanilla extract, and vegetable oil. Stir gently with a spoon or whisk just until everything is combined. Be careful not to overmix, as this can make the cake dense instead of soft and tender.

Pour the batter into the pan and bake for roughly half an hour. Start checking around 25 minutes by inserting a toothpick into the center, if it comes out with a few moist crumbs, your cake is perfectly baked.

Rest the cake 5 minutes in the pan, then transfer to a wire rack to cool. It’s important to let it cool fully before frosting; otherwise, the frosting won’t hold up well.

To make the Nutella frosting, soften your Nutella by heating it in the microwave for about 20 seconds, just enough so it’s easy to stir, but not hot.

In a mixing bowl, stir together Nutella, heavy cream, mascarpone, powdered sugar, and salt. Whip from low to medium-high until stiff, fluffy peaks form.

Spread the frosting generously over the top and get ready to enjoy every rich, creamy bite.