Combine first four ingredients in a mixing bowl; stir. Press firmly in bottom and 1 inch up sides of a 10-inch springform pan. Chill.
Preheat oven to 300 degrees.
Beat cream cheese
in a mixing bowl with an electric mixer at medium speed until creamy. Gradually add sugar, beating well.
Add eggs, one at a time, beating well after each addition.
Add sour cream and Amaretto, beating at low speed until smooth. Pour into prepared pan.
Bake for 1 hour and 30 minutes; turn oven off. Leave in oven with door closed for 4 hours.
Melt remaining butter in a small saucepan over medium heat on stovetop. Add remaining almonds and sugar. Cook until almonds are golden, stirring often. Cool.
from oven. Gently run a knife around edge of pan to release sides. Cool completely in pan on a wire rack. Sprinkle topping over cheesecake. Cover and chill for 8 hours.
Remove sides of pan before serving.