Preheat the oven to 350 degrees F. Arrange the hazelnuts in a single layer on a silicon pad lined baking sheet. Put the tray in the center of the oven and cook until a little past light brown, 8 to 10 minutes. Set aside to cool.
Heat a large, stainless steel pan on medium heat. Make sure the pan is dry and clean to avoid any impurities or water affecting the caramel you are about to make. Add the sugar. Shake the pan slightly to distribute the sugar in an even layer on the bottom of the pan. Lower the heat and keep your eye on the sugar as it melts and begins to turn brown. Lift the pan and swirl the sugar around from time to time as it melts. Do not stir with any utensils. Any impurities on the utensil could also disturb the sugar as it melts.*
Prepare a baking sheet lined a silicon mat or parchment paper. Spray a layer of nonstick spray on the parchment, if using. Set aside. When the hazelnuts cool slightly and the caramel is a light brown, use a clean spoon to stir the hazelnuts into the caramel. Spray the spoon with nonstick spray so that the sugar doesn't stick to the end of the spoon as you work. Stir the nuts, coating them with the sugar. Use the spoon to scoop out the hazelnuts and spread them on to the lined baking sheet. Spread them as best you can without creating big clumps. Sprinkle with a touch of salt. Set aside to cool.
In a medium bowl, whisk together the eggs, almond extract and the lemon zest. Set aside.
In another bowl, sift together the 1/4 teaspoon kosher salt, flour, baking powder, baking soda and cinnamon. Set aside.
Stir the flour into the egg mixture. Use your hands to finish combining the wet and dry ingredients. Break apart and roughly chop the hazelnuts and gently work half of them into the dough. Reserve remaining half for snacking.
Prepare a baking sheet lined with parchment paper and lightly spray with cooking spray.
Divide the dough into 2 equal parts. Using your hands, turn the dough out onto a lightly floured flat surface. Form each half of the dough into a loaf-like shape about 2 inches wide and about 12 inches long. They should look like 2 loaves of bread. Carefully arrange the 2 loaves, side by side, on the baking sheet. For optimum baking, leave as much space as possible between the loaves.
Put the baking sheet in the center of the oven and bake, undisturbed, for 25 to 30 minutes. The dough should be light brown and may rise a little as it cooks. Remove from the oven and put onto a flat surface to cool. Turn the oven off.
Once cooled, using a serrated knife, gently saw the loaf into 1/2-inch thick slices, cut on an angle. Arrange the slices on the baking sheet, cut sides up, in a single layer. There should be a little space between each slice. It will almost feel like the loaves are 2 puzzles that you take apart by cutting and then put back together on the baking sheet.
Return the baking sheet to the oven. Allow them to sit in the oven for 10 minutes. This will cause the biscotti to firm up and toast, but only ever so slightly. Remove from the oven and cool. Serve with lemon curd.
In a large, stainless steel pot, whisk together the eggs, granulated sugar, lemon zest and orange zest. Continue to whisk until the mixture lightens in color, 2 to 3 minutes. Whisk in the lemon juice and orange juice.
Put the pot over low heat and cook and stir constantly, until the mixture starts to thicken. Take care to scrape the sides of the pot so the curd doesnt form a crust on the edges or scorch as it cooks. After a few minutes, start gradually whisking in the slices of butter. When all of the butter is integrated, remove the pot from the heat. Transfer the curd to another bowl to cool, then cover it tightly with a layer of plastic wrap. The plastic should be placed directly on top of the curd to prevent a skin from forming as it cools.
Serve in a bowl alongside the biscotti for dunking or spreading on the biscotti like jam.
Yield: about 1 to 1 1/2 cups curd
Prep Time: 10 minutes
Cook Time: 10 minutes
Inactive Prep Time: 30 minutes
Ease of preparation: easy
* Add some water if you are afraid of burning the sugar. If the caramel starts to cool and become thick, heat it gently (over low heat) for a minute or two. That will loosen the sugar.