• Preheat the oven to 350°F. Lightly spray three 8″ round cake pans with non-stick spray and dust with flour, tapping the pan afterward so that all excess flour is removed.
• In a large bowl with an electric mixer, beat the butter until smooth. Add the brown sugar, granulated sugar, and oil and beat for 2 to 3 minutes.
• Add the eggs and beat on low speed until completely combined.
• Add the buttermilk and vanilla and beat on low speed until smooth.
• Add the baking powder, cinnamon, ginger, baking soda, and salt and beat on low speed until smooth.
• Add the flour and mix on low speed, just until no visible streaks of flour remain. Stir in the carrots and walnuts or pecans, if using.
• Divide the batter between the prepared cake pans.
• Bake for 18 to 20 minutes, until a toothpick inserted in the center comes out clean or with moist crumbs. Let cool for 10 minutes before transferring the cake layers to a wire rack to cool completely before frosting.

Whipped Cream Cheese Frosting

• In a medium bowl with an electric mixer, beat the cold cream cheese until smooth.
• Add the powdered sugar and vanilla and beat until combined, scraping down the bowl as necessary.
• Add the cream, a little bit at a time, and beat on low speed until incorporated. Turn the mixer to high and beat until fluffy and thickened. (This doesn't take too long, just a couple minutes! Over-mixing will make the whipped cream thin again, so watch carefully. When you pull the beaters out of the bowl and have stiff peaks, it’s ready.)
• Divide the frosting between the cake layers to assemble. Top with additional chopped nuts as desired.