Preheat oven to 350F.

Butter two 9-inch cake pans. Line bottom of pans with waxed paper or parchment. Butter and flour paper. Remove excess flour.

Whisk flour, baking soda, salt and cinnamon in medium bowl or mechanical mixer. In a separate bowl beat sugar and oil until well blended. Add eggs 1 at a time. Add flour mixture and stir until blended. Stir in carrots, walnuts and ginger. Divide mixture between prepared pans.

Bake cakes until tester inserted into center comes out clean, about 40 minutes. Cool cakes in pans 10-15 minutes. Turn out onto racks. Peel off waxed paper; cool cakes completely.

For icing: Beat cream cheese and butter in large bowl until airy. Add powdered sugar and beat at low speed until combined. Add maple syrup and beat. Chill until just firm enough to spread, 30 minutes.

Place 1 cake layer on platter. Spread with 3/4 cup icing. Top with second layer. Spread remaining icing over entire cake. Arrange walnut halves around top edge.

Serve at room temperature. This cake will keep one day in the refrigerator.