In a stand mixer fitted with the whisk attachment, beat the eggs on medium speed. Gradually add the sugar and brown sugar and whip for about 4 minutes, until the mixture is pale and fluffy.

Add the vanilla and oil, and whisk briefly by hand. Add the instant coffee, flour, baking powder, and water. Mix just until smooth and well combined.

Pour the batter into the prepared pan and bake for about 45 minutes, or until a toothpick inserted in the center comes out with moist crumbs. Let the cake cool completely at room temperature.

Place the chopped chocolate and cream in a microwave-safe bowl. Heat in short pulses in the microwave, stirring in between, until melted and smooth. Transfer to a wide bowl, cover with plastic wrap, and chill for 1 hour.

Once the cake has cooled, use a serrated knife to slice it horizontally into two even layers. Place the bottom layer on a serving plate, spread the chilled ganache over it, and top with the second cake layer. Refrigerate until ready to frost.

In a stand mixer fitted with the whisk attachment, whip the cream, powdered sugar, and pudding powder on medium speed until soft, stable peaks form. Spread the whipped cream evenly over the top of the cake with an offset spatula. Dust with cocoa powder and sprinkle with grated chocolate. Serve chilled or at room temperature.