- With the rack in the middle position, preheat the oven to 180 °C (350 °F). Butter and line a 20-cm (8-inch) square pan with a strip of parchment paper, letting it extend over both sides. Set aside.
- In a food processor, combine flour and icing sugar. Add butter and pulse until dough is just moistened. Press into the bottom of the prepared pan. Bake for 15 minutes or until edges of dough are lightly browned.
- Meanwhile, in the bowl of a food processor, combine cheese and sugar. Add egg and mix thoroughly. Scrape the sides of the bowl a few times during this process. Add chocolate and combine until smooth.
- Pour into a bowl, add blueberries and gently stir with a spatula. Spread over warm dough. Bake for 25 to 30 minutes or until the filling edges are set, but the centre is still slightly wobbly. Let cool. Refrigerate until completely chilled.
- Cut into squares.