Heat oven to 350 degrees F. In large pan bring water to boil, add parsnip pieces, and cook until easily pierced. Drain. Combine the parsnips with the next 7 ingredients, mash well. Pour into pie shell and bake until a knife blade comes out clean, about 30 to 40 minutes.
While pie is still warm, spread with marmalade (you may strain it if you want a more glazelike topping) and sprinkle with the sliced almonds.