Preheat oven to 350 degrees.
Beat butter and sugar until blended. Beat in egg and almond extract. In separate bowl combine flour, baking powder and salt; pour over batter and stir until blended. Pat over bottom and 2 inches up side of greased 10-inch springform pan. Set aside.
Filling:
Toss together blueberries, liqueur and lemon rind; scrape over crust. Whisk together sour cream, egg yolks, sugar and almond extract; scrape evenly over blueberries. Bake for 1 1/4 hours or until crust is golden and crisp. Let cool in pan on rack. Refrigerate for 4 hours or until chilled. Remove side of pan.
Cut into wedges to serve. For an added touch, pipe whipped cream over tart and decorate with thin candied orange strips and almond slivers
