1. Preheat oven to 350 degrees. Sift flour and confectioners' sugar. Cut in butter until mixture clings together.
2. Press into 13x 9 inch pan and bake 20-25 minutes or until slightly browned. While crust is baking prepare topping by beating eggs together with the sugar and lemon juice.
3. Sift flour and baking powder and stir into egg mixture.
4. Pour over crust and bake an additional 25 minutes. Cool, and then cut into individual portions. Serve with a small pile of blueberries, a dollop of cream, a mint leaf and a dusting of confectioners' sugar.