Makes one 8 or 9-inch layer cake

adapted from Fine Cooking November 2001

For the Cake:

2 medium beets, unpeeled but trimmed of their greens

1 teaspoon vegetable oil

6 ounces (3/4 cup) unsalted butter, softened, plus more for greasing the pans

1 cup packed brown sugar

3/4 cup granulated sugar

2 large eggs

1 teaspoon pure vanilla extract

2 cups all-purpose flour, plus more for dusting the pans

2/3 cup unsweetened cocoa powder

1 teaspoon baking soda

1/2 teaspoon baking powder

1 teaspoon salt

1 1/4 cups buttermilk

For the Frosting:

1 cup (2 sticks) unsalted butter, softened

8 ounces (1 brick) cream cheese, softened

4 to 5 cups powdered sugar, sifted

2 tablespoons finely grated beets, mashed with a fork

1 teaspoon pure vanilla extract or scrapings of one vanilla bean pod

1-2 teaspoons milk, depending on desired consistency

1/2 teaspoon fresh lemon juice

pinch of salt