Cook the cut-up asparagus, covered, in the boiling water for about 10 minutes or until tender. Cool slightly. Transfer asparagus and cooking liquid to a blender container or food processor bowl; cover and blend or process until pureed. (You should have 2 cups; add water if necessary.) Set aside.
In a large mixing bowl, beat butter with an electric mixer on medium to high speed for 30 seconds or until softened. Add brown sugar and beat until well combined. Beat in eggs.
In another bowl, stir together flour, baking powder, baking soda, cinnamon, nutmeg, and salt. Add to creamed mixture alternately with asparagus puree, beating until just combined after each addition. With a wooden spoon, stir in nuts, dates and raisins.
Pour into 2 greased and floured 8x1-1/2-inch or 9x1-1/2-inch round baking pans or one 13x9x2 inch baking pan.
Bake in a 350 degree F oven for 40 to 45 minutes for the 8-inch pans, 35 to 40 minutes for the 9-inch pans and about 30 minutes for the 13x9x2-inch pan or until a toothpick inserted near the centers comes out clean.
Cool on wire racks for 10 minutes. Remove round layers from pans. Cool thoroughly on racks. Frost top of one layer with Cream Cheese Frosting. Place second layer on top; frost top and sides. (For 13x9x2-inch cake, leave in pan and frost only the top.) Makes 16 servings.
To prepare asparagus, wash and scrape off scales, if you like. Break off the woody bases at the place where the spears snap easily.