How to Make It
Preheat the oven to 300°. Spread the pecans on a small rimmed baking sheet and toast, tossing them halfway through, for about 20 minutes, until browned. Transfer to a work surface and let cool, then coarsely chop.
Line 2 rimmed baking sheets with parchment paper. In a stand mixer fitted with the whisk, beat the egg whites at medium-high speed until foamy, about 30 seconds. Beat in the sugar 1 tablespoon at a time until the whites are stiff and glossy, 5 to 7 minutes. Beat in the grappa, cinnamon, nutmeg and cloves. Using a rubber spatula, gently fold in the chopped pecans.
Spoon heaping tablespoons of the meringue onto the prepared baking sheets, spaced 1 inch apart. Bake for 15 minutes. Reduce the oven temperature to 200° and bake for 1 hour and 15 minutes, until the meringues are firm on the outside but still chewy in the center. Transfer the baking sheets to wire racks and let cool completely.