Prepare the rolled biscuit:

Preheat the oven to 180°C and line a baking tray with baking paper.

Separate the egg whites from the egg yolks. Beat the yolks with the sugar until the mixture whitens. Add the cornstarch, almond powder and a teaspoon of dissolved coffee.

Beat the egg whites until stiff with a pinch of salt. Gently incorporate them into the previous mixture.

Spread the dough on the baking sheet and bake for 10 to 12 minutes, until the biscuit is lightly golden.

Remove the biscuit from the oven, immediately turn it over on a clean, damp cloth. Carefully remove the parchment paper and roll the biscuit in the towel. Leave to cool.

Prepare the filling:

Melt the chopped white chocolate in a bain-marie or in the microwave. Add the mascarpone and a teaspoon of coffee, then mix until you obtain a smooth ganache. Let cool to room temperature.

Let the ganache cool.

Assemble the log:

Gently unroll the biscuit and spread an even layer of white chocolate and coffee ganache. Sprinkle with crushed pecans.

Roll the biscuit on itself, tightening slightly, then cover it with the rest of the mascarpone-white chocolate ganache. Refrigerate for at least 2 hours so that the log sets well.

Decorate the log:

After an hour, when the ganache has firmed up but is still tender, you can use a fork to streak the log. Then decorate with some pecans.

For an extra touch, you can add a few drops of diluted coffee to the surface to intensify the flavors.