Preheat oven to 325°. Grease and flour two 9” round baking pans.
Stir together flour, baking soda, cinnamon, ginger and salt in a bowl and set aside. In another bowl, using a mixer set at medium speed, beat eggs, honey, vanilla, sugar, mayonnaise until well blended. Gradually beat in flour mixture until well mixed. With a spoon, stir in parsnip, pear and walnuts.
Evenly pour into pans and bake at 325°F for 30-35 minutes.
CREAM CHEESE FROSTING: Using a mixer beat the ingredients on medium speed until smooth.
MAKING SUGARED ROSEMARY: Boil water with 1cup sugar in a saucepan. Once cooled, dunk rosemary in syrup and roll in remaining sugar. Shake off any excess sugar and let dry.
TO ASSEMBLE THE CAKE: Make sure cakes are completely cooled before assembling. Evenly spread a layer of cream cheese frosting in between each cake layer and cover the outside with more frosting. Decorate with chopped walnuts and candied rosemary.