1. Cut vanilla bean lengthwise, and remove seeds from it. Set aside.
2. In a 9x13-inch baking dish, line half cookies. Pour little coffee on each of them.
3. In a bowl combine egg yolks and vanilla seeds. Whisk until it starts to change color.
4. Throw sugar, little at a time, beating continuously.
5. Drop salt, and whisk until creamy consistency.
6. Add mascarpone and whip for a couple of minutes.
7. Spoon half of the batter on top of cookies. Spread evenly.
8. Lay remaining cookies on top, cover them with coffee, and spread remaining mascarpone mixture on it.
9. Clean up edge of baking dish, cover it with saran wrap, and pop it in refrigerator for about 1-4 hours or until set.
10. For topping, in a small bowl, combine sugar, walnut, and cocoa powder. Mix well.
11. Spread topping evenly on cake.
12. Cut in slices and serve tiramisu chilled.
You can add flavoring to your coffee like hazelnut liqueur.
Use any nut for topping. You can chop and caramelize them to add extra flavor.