Carrot Cake with Cream Cheese Frosting

INGREDIENTS

• 1 tablespoon pure vanilla extract
• 1/2 teaspoon freshly grated nutmeg
• 11 tablespoons unsalted butter, softened at room temperature
• 1 tablespoon unsalted butter, for greasing the pans
• 3/4 teaspoon baking soda
• 1 1/3 cup confectioners' sugar, sifted after measuring
• 2/3 cup dark or golden raisins
• 1/4 teaspoon ground allspice
• 2 teaspoons ground cinnamon
• 1 cup safflower or canola oil
• 2 (8-ounce) packages cream cheese, chilled
• 4 large eggs, at room temperature
• 1 pound carrots, trimmed, peeled, and coarsely grated on the largest holes of a box grater or the fine grating blade of food processor (about 3 lightly packed cups total)
• 2 cups packed light brown sugar
• 1 teaspoon baking powder
• 2 cups unbleached all-purpose flour
• 2/3 cup walnuts or pecans, coarsely chopped, plus more lightly toasted nuts for garnish
• 3/4 teaspoon fine sea salt or table salt