- Preheat oven to 350 F. Butter and flour 13x9x2-inch baking pan.
- Combine flour, sugar, ground ginger, baking powder, cinnamon, 3/4 teaspoon salt, nutmeg, allspice, and cloves in large bowl. Whisk to combine.
- Whisk together eggs, oil, milk, and 1 teaspoon vanilla in medium bowl. Pour egg mixture over dry ingredients. Stir until just combined. Stir in parsnips and walnuts.
- Transfer batter to prepared pan. Bake until tester inserted into center comes out clean, about 25 minutes. Cool cake completely in pan on rack.
- Beat cream cheese and butter in large bowl until smooth. Beat in fresh ginger and remaining 1/8 teaspoon salt and 1/2 teaspoon vanilla. Gradually add powdered sugar and beat until frosting is smooth. Spread over cake.
Recipe and photo from bonappetit.com.