Start by preparing your hot coffee - you can use any brewing method of your choice or make instant coffee. Pour the hot coffee out into a medium sized bowl, so that it can cool down slightly.
Beat the heavy creamy to stiff peaks. Set aside.
In a separate bowl, mix the mascarpone, sugar and vanilla until light and fluffy.
Then gently fold in the whipped cream into the mascarpone mixture until smoothly combined.
Lightly dip the sponge cake slices into the coffee (do so quickly so the cake doesn’t become soggy!) and line a glass/ ceramic dish with a layer of these soaked cake slices.
Spread a generous layer of mascarpone on top and dust with cocoa powder.
Repeat the process again and dust with cocoa powder to finish.
Refrigerate for a few hours/ overnight until set ; then enjoy!