Method

Preheat oven to 350°F (180°C).

In large bowl, beat butter with sugar until blended. Beat in egg and almond extract.

In separate bowl, whisk together flour, baking powder and salt ; pour over batter and stir until blended. Pat over bottom and 2 inches (5 cm) up side of greased 10-inch (3 L) springfrom pan. Set aside.

Filling:
Toss together blueberries, liqueur and lemon rind; scrape over crust. In bowl, whisk together sour cream, egg yolks, sugar and almond extract; scrape evenly over blueberries.

Bake in centre of oven 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.