Combine margarine and sugar until light and fluffy. Blend in egg. Add flour; mix well. Spread dough onto bottom of a 9-inch springform pan. Bake at 450 degrees F for 10 minutes.
Combine cream cheese, sugar and flour, mixing at medium speed of electric mixer until well blended. Add eggs, one at a time, mixing well after each addition. Add peaches and liqueur; mix well. Pour over crust. Bake at 450 degrees F for 10 minutes. Reduce oven temperature to 250 degrees F. Continue baking for 65 minutes. Loosen cake from rim of pan; cool before removing rim of pan. Chill.
Garnish with peach slices and sliced almonds, toasted, if desired.
Source: E-Cookbooks.net