Carrot Cheesecake

3/4 pound carrots, peeled and cut into 2-inch pieces
2/3 cup fine graham cracker crumbs
2/3 cup fine gingersnap crumbs
2/3 cup finely ground pecans
1/3 cup granulated sugar
4 tablespoons unsalted butter, softened
1/2 cup packed brown sugar
1 tablespoon lemon juice
1 teaspoon grated orange zest
1 teaspoon minced ginger root
1/4 teaspoon ground cinnamon
1/4 teaspoon mace
1/4 teaspoon allspice
16 ounces cream cheese, cut into small cubes and softened
4 eggs
1/4 cup finely chopped pecans

Bring 4 cups of water to a boil, and cook carrots until very tender - about 45 minutes. Drain cooked carrots. Return them to a moderate heat for a minute or so to cook off excess moisture.

Preheat oven to 400 degrees F.

In a medium bowl, combine graham cracker crumbs, gingersnap crumbs, the 2/3 cup ground nuts, and sugar; toss well. Work in butter until mixture is crumbly. Pat over bottom and up sides of a buttered 9 inch springform pan. Bake the crust for 7 minutes. Turn oven down to 350 degrees F.

Transfer carrots to food processor and pur