Preheat oven to 350 degrees. In a large bowl, cream together the butter and 3/4 cup sugar until smooth. Mix in egg. In a separate bowl, combine the flour, cream of tartar, baking soda and salt; stir into the creamed mixture until just blended.
Press dough into an ungreased pizza pan, using the palm of your hand. This takes some time, so be patient. Bake in preheated oven for 8 to 10 minutes, or until lightly browned. Allow to cool completely.
In a large bowl, beat cream cheese with 1/2 cup sugar and vanilla until light and fluffy. Spread onto cooled crust. Arrange desired fruit on top of filling, chill until ready to serve. Use a knife and metal spatula to remove pizza from the pan.
Cook's Note: For a quick crust, use one package of ready- made sugar cookie dough rolled out to fit a pizza pan and bake as directed. Use an assortment of fresh fruit. I used 1 lb. strawberries cut into thirds, 2 bananas, 3 nectarines, 5 kiwis, and a 1/4 cup of blueberries. If using bananas, place them on just before serving as the turn brown quickly.