1 c. chopped walnuts or pecans
1 c. flour
1/2 c. brown sugar
6 tbsp. melted butter

Finely chop nuts either by hand or in food processor or blender. Blend in butter, flour and brown sugar. Press in bottom of springform pan. Bake at 350 degrees for 10 minutes.

FILLING:

1 1/4 sticks soft butter (10 tbsp.)
1 2/3 c. powdered sugar
8 oz. melted semi-sweet chocolate
1/4 c. liqueur, optional
2 eggs
Whipped cream
Chocolate shavings or chopped nuts (optional garnish)

Cream butter and sugar. Blend in melted chocolate. Blend in liqueur. Beat in eggs one at a time. Pour into baked crust. Chill well. Serve with whipped cream and garnish (if desired).