1Heat oven to 325°F. In small bowl, mix crust ingredients. Press on bottom and 1 1/2 inches up side of 9-inch springform pan. Bake 8 to 10 minutes or until set. Cool 10 minutes.
2Beat cream cheese, sugar and 1 teaspoon vanilla with electric mixer on medium until smooth. Beat in eggs, one at a time, just until blended. Beat in pumpkin and lemon juice. Pour over crust. Bake 1 hour to 1 hour 10 minutes or until edge is set 2 inches from edge of pan (center will jiggle). Turn oven off; open door 4 inches. Leave cheesecake in oven 30 minutes. Run small metal spatula around edge of pan to loosen. Cool 30 minutes. Refrigerate 6 hours.
3In 1-quart saucepan, heat 1 cup brown sugar, the whipping cream and 1/4 cup butter to boiling over medium heat, stirring often. Boil and stir 1 minute; remove from heat. Stir in powdered sugar and 1 teaspoon vanilla. Let stand 5 minutes, stirring occasionally. Remove side of springform pan; place cheesecake on serving plate. Pour topping over cheesecake, spreading to within 1/4 inch of edge. Garnish with pecan halves, if desired.