To make Mandolato: Line an 8 x 8 inch baking pan with parchment paper. Butter any part of the pan that isn't covered with parchment paper. Set aside. Note: I prefer a thinner Mandolato, so I use an 8 x 8 inch pan which produces about a 1/2 inch thickness. If you prefer it thicker, use a 9 x 5 loaf pan.

Toast almonds and pistachios in a 350ºF (180ºC) oven for about 12 min (shake tray half way through). Keep nuts warm after toasting.

In a stand mixer with whisk attachment, add two room temperature egg whites and cream of tartar. Turn stand mixer on at a medium-low speed, keeping the egg whites at very frothy level until sugars have boiled (next step).

Place sugar, honey, corn syrup, and water in a medium sized saucepan over medium heat. Stir constantly until the sugar dissolves. Using a candy thermometer, boil until 250 F (130 C); still stirring. Just before the sugars reach the 250 F (130 C) mark, turn the stand mixer on high so that peaks start to form on the egg whites.

As soon as sugar temperature reaches 250 F, take off heat and carefully pour approximately 1/4 cup of the boiled sugars in a very thin stream into the egg whites. Leave to beat on high for about 5 minutes Return the remaining sugar mixture to medium heat, stirring and cooking until thermometer reaches 295 F - 300 F (150 C).

Take off heat and pour remaining sugar in a thin stream into the egg whites. Beat for another 3 minutes. Add vanilla and butter and beat for another 5 minutes on medium-high.

Add the warm toasted nuts and mix by hand with a spoon to combine. Spoon mixture into the pan.

Butter your hand and press mixture into pan and smooth the top nicely. Leave for a couple of hours to harden.

Loosen the mandolato on the sides of the pan with a knife if needed, and lift out of the pan with the parchment paper. Cut into one inch squares with a serrated knife.

See more delicious desserts here. Enjoy!