Here is a nice simple recipe from http://www.canadianliving.com/ which you might like to try.
2-1/2 cups (625 mL) rolled oats, (not instant)
1-1/4 cups (300 mL) all-purpose flour
1 tbsp (15 mL) grated orange rind
1/4 tsp (1 mL) salt
1 cup (250 mL) cold butter, cubed
3/4 cup (175 mL) packed brown sugar
3 cups (750 mL) fresh blueberries
1/2 cup (125 mL) granulated sugar
1/3 cup (75 mL) orange juice
4 tsp (18 mL) cornstarch
Filling: In saucepan, bring blueberries, sugar and orange juice to boil; reduce heat and simmer until tender, about 10 minutes. Whisk cornstarch with 2 tbsp (25 mL) water; whisk into blueberries and boil, stirring, until thickened, about 1 minute. Place plastic wrap directly on surface; refrigerate until cooled, about 1 hour.
In large bowl, whisk together oats, flour, sugar, orange rind and salt ; with pastry blender, cut in butter until in coarse crumbs. Press half into 8-inch (2 L) square parchment paper–lined metal cake pan; spread with blueberry filling. Sprinkle with remaining oat mixture, pressing lightly.
Bake in centre of 350°F (180°C) oven until light golden, about 45 minutes. Let cool on rack before cutting into squares. (Make-ahead: Cover and refrigerate for up to 2 days or overwrap with heavy-duty foil and freeze for up to 2 weeks.)