Blackberry-Almond Shortbread Squares

Directions

1. 1
   Preheat oven to 350 degrees.
2. 2
   Butter a 9-by-13-inch baking pan.
3. 3
   Line with parchment; butter lining.
4. 4
   Dust with flour; tap out excess.
5. 5
   Arrange nuts in a single layer on a rimmed baking sheet.
6. 6
   Bake until golden, 15 minutes; let cool.
7. 7
   Grind in a food processor until fine.
8. 8
   Whisk together flour, nuts, salt and cinnamon in a medium bowl; set aside.
9. 9
   Put 3/4 cup plus 1 tablespoon sugar and the butter in the bowl of an electric mixer fitted with the paddle attachment; mix until pale and fluffy, about 3 minutes.
10. 10
    Mix in almond extract.
11. 11
    Add flour mixture in 2 batches; mix until a crumbly dough forms.
12. 12
    Press all but 1 cup dough onto bottom of pan.
13. 13
    Toss berries with zest; scatter over dough.
14. 14
    Sprinkle with remaining tablespoon sugar; crumble reserved dough on top.
15. 15
    Bake until golden, about 30-40 minutes.
16. 16
    Let cool completely on a wire rack.
17. 17
    Cut into 12 squares; dust with sugar.