In a large bowl, combine flour and 3/4 cup sugar. Using pastry blender or fork, cut in butter until crumbly. Reserve and set aside 1 cup of crumbs for the topping. To the remaining crumb mixture, add baking powder, baking soda, salt, sour cream, almond extract, and 1 egg and mix until well blended. Spread batter over bottom and up the sides of greased and floured 9-inch springform pan.