Preheat the oven to 160°C (320°F). Grease and flour a baking tray (29 x 24 x 7 cm), or use parchment paper to line it.

In a large bowl, whisk together the milk, oil, and sugar. Mix for about a minute using a hand mixer or whisk until combined.

Add the instant coffee powder and boiling water to the mixture, stirring until the coffee dissolves. Then, add the eggs one at a time, mixing well after each addition.

In a separate bowl, sift together the flour, cocoa powder, baking powder, salt, and cornstarch. Gradually add the dry ingredients to the wet ingredients, mixing until just combined (don’t overmix).

Pour the batter into the prepared baking tray and bake for 45-50 minutes, or until a toothpick inserted into the center of the cake comes out clean.

Allow the cake to cool completely in the pan.

In a saucepan over low heat, melt together the butter, chocolate, and whipping cream, stirring constantly. Be careful not to bring it to a boil; the goal is to melt the ingredients slowly and evenly.

Once the ganache is smooth and fully melted, remove it from the heat and allow it to cool to room temperature.

Once cooled, pour the ganache onto the cooled cake in the baking tray. You can use a spatula to spread it evenly across the top.

Refrigerate for at least 5 hours, or overnight, for best results. Add raspberries when the ganache is still soft but stiff.