Coffee Soak

1. Sift the cocoa powder into a medium-sized shallow bowl
2. Add the sugar and mix until combined
3. Slowly pour in the coffee, stirring until completely combined
4. Set aside to cool to room temperature

Chocolate Ganache

1. Combine the heavy cream and chocolate in a large heat-proof bowl and place it over a small saucepan filled with boiling water
2. Melt the chocolate and cream together over the hot water bath until completely melted
3. Remove from the heat and set aside to cool to room temperature

Mascarpone Cream

1. Combine the egg yolks and sugar in the bowl of a stand mixer fitted with a whisk or in a large mixing bowl with an electric mixer and beat together until lightened in color and doubled in volume
2. Add the mascarpone cream and rum, and whisk until it reaches stiff peaks
3. In another bowl whip the cream until stiff peaks
4. Add the cream to the mascarpone mixture and fold together until just combined
5. Set aside in the fridge until ready to assemble

Assembly

1. Prepare a medium-sized rectangular baking dish (mine was 30cm x 19cm / 11" x 7.5") or a large rectaingular cake pan
2. Spread a thin layer of mascarpone cream over the base of your baking dish
3. Dip the ladyfingers in the coffee soak and line them up along the base of the baking dish, making sure to cover the entire surface
4. Top with a layer of mascarpone cream
5. Top the cream with a thin layer of the chocolate ganache
6. Place down another layer of soaked ladyfingers, the remaining cream, and the remaining chocolate ganache
7. Smooth off the top of the ganache and cover it with cling wrap
8. Place the assembled tiramisu in the fridge to chill overnight or a minimum of 4 hours
9. Remove the chilled tiramisu from the fridge and dust it with cocoa powder
10. Slice and enjoy!