Special equipment: Six 6- to 8-ounce shallow ramekins; a kitchen blowtorch
Preheat the oven to 300 degrees F. Put six 8-ounce ramekins on a rimmed baking sheet or in a large, shallow baking dish.
For the custard: Put the heavy cream, 2 tablespoons granulated sugar, 2 tablespoons light brown sugar, the cloves, cinnamon and nutmeg in a small saucepan over medium-high heat and cook, stirring occasionally, until the sugar dissolves and the cream comes to a bare simmer. Meanwhile, whisk together the egg yolks, 2 tablespoons of the remaining granulated sugar and 2 tablespoons of the remaining light brown sugar in a medium bowl.
Slowly whisk the hot cream into the egg yolk mixture. Strain the custard into a pitcher or large measuring cup. Divide the custard evenly among the ramekins. Place the baking sheet in the oven, then carefully add enough hot water to come halfway up the sides of the ramekins. Bake until the custards are just set at the sides and still wobbly in the center, about 30 minutes. Remove the ramekins from the water and let cool completely on a wire rack, about 30 minutes. Leave the oven on.
For the garnish: While the custards cool, spread the pecans on a baking sheet and bake until they are brown and toasty-smelling, about 10 minutes. Whip the cream in a medium bowl until soft peaks form.
To assemble: Sprinkle the remaining 3/4 cup granulated sugar evenly over the tops of the custards. Using a kitchen torch, cook the tops until the sugar melts and turns deep amber. Allow the sugar to harden, about 2 minutes. Top each creme brulee with a dollop of whipped cream, 3 pecans, a fresh raspberry and a mint sprig, if using. Dust with some confectioners' sugar and serve.
Propane gas torches are highly flammable and should be kept away from heat, open flame and prolonged exposure to sunlight. They should be used only in well-ventilated areas. Follow torch manufacturer's instructions for use.