Preheat the oven to 400 degrees F (200 C) then line 2 baking trays with parchment and grease with butter or oil. Place egg whites in the bowl of a stand mixer with whisk attachment and beat until soft peaks form, Slowly add in 2 tablespoons of sugar and continue beating until stiff peaks form.
Scrape whites into a separate medium bowl and add yolks and 2/3 cup sugar to mixer bowl. Beat until light in color and frothy. Add extracts, salt, and baking powder and mix well.
Fold in egg white mixture with a rubber spatula until mostly mixed, then sift in flour and continue folds until evenly combined.
Fit a piping bag with a 1/2 inch round tip and fill with mixture. Pipe into 4 1/2 inch lady fingers, about 1/2 inch apart on trays. Dust with powdered sugar and bake for 10 to 12 minutes or until lightly browned on the outside. Remove and cool.
Combine yolks and sugar in the bowl of a stand mixer (no need to wash after lady fingers) and beat until light in color. Add mascarpone, salt, and vanilla and beat until smooth. You should have about 3 cups, so take 1 1/2 cups out and add nutella to the remaining mix and beat until creamy smooth.
You can make this in a trifle dish, 13x9 pan, or individual glasses. Mix coffee and Kahlúa in a small bowl and dip lady fingers as you add them. Layer coffee dipped lady fingers, then white cream, then nutella cream, then a dusting of cocoa and repeat layers until dish or glasses are full.
If you can't find macarpone you can replace it with: 2/3 cup softened cream cheese, 1/3 cup heavy whipping cream, and 2 tablespoons sour cream, beaten together until smooth