Pour the egg yolks and Hermesetas Granulated Sweetener into a bowl and whisk until the mixture is light and thick. Add the mascarpone and whisk until the mixture reaches a fine, uniform consistency. Pour the egg whites into a new bowl and whisk until they are stiff and airy. Gently fold the egg whites into the mascarpone mixture, taking care to retain the volume. Mix the coffee and amaretto together in a bowl. Briefly dip a lady finger into the coffee mix and place it at the bottom of a dish or cake tin (approx. 24 x 15cm). Continue until the entire base is covered with a layer of lady fingers. Pour half of the mascarpone cream over the layer of lady fingers and spread evenly. Repeat with a new layer of lady fingers and finish by spreading the rest of the mascarpone cream on the top. Place the tiramisu in the fridge for four hours. Sprinkle cocoa powder over the cake just before serving.