For the cake: – 2 cups all-purpose flour – 2 teaspoons baking soda – 1 teaspoon pumpkin pie spice – 1/2 teaspoon ground cinnamon – 1/2 teaspoon salt – pinch of ground nutmeg – 15 ounce can pure pumpkin puree – 1 cup light brown sugar packed – 1 cup granulated sugar – 1 cup vegetable oil – 4 large eggs – 1 teaspoon vanilla extract For the frosting: – 8 tablespoons salted butter – 1 cup dark brown sugar packed – 1/2 cup heavy cream – 2 cups powdered sugar – 2 tablespoons bourbon – 2 teaspoons vanilla extract – 1 & 1/2 cups chopped toasted pecans – 1/2 teaspoon salt