Preheat the oven to 350°. In a bowl, cover the pecans with water. Transfer to a sieve and shake out the water. In another bowl, whisk the confectioners' sugar, cayenne and 1 1/2 teaspoons of salt. Add the pecans and toss. Transfer to a sieve and shake off the excess coating. Arrange the pecans on a parchment paper–lined baking sheet and bake for 10 to 12 minutes, until the sugar is lightly caramelized and the pecans are golden. In a skillet, heat the oil with the pancetta and cook over moderate heat, stirring frequently, until the pancetta is browned, 6 minutes. Strain the pan drippings into a large bowl; whisk in the vinegar, caper brine and maple syrup and season the dressing with salt and black pepper. Add the apples, radicchio, kale, chives, tarragon and pecorino and toss. Mound the salad on plates, garnish with the pecans and pancetta and serve.