Blackberry Oat Bars

Blackberry Oat Bars
Adapted from Williams-Sonoma: Essentials of Baking
1 3/4 cups all-purposed flour
1 1/2 cups old-fashioned rolled oats
1 cups firmly packed brown sugar
1 tbsp ground cinnamon
1 cup cold unsalted butter, cut into 3/4 inch pieces
1 cup blackberry jam

Position a rack in the middle of the oven and preheat to 325 degrees. Butter a 9-inch square baking pan.

Combine the flour, oats, brown sugar, and cinnamon and pulse a few times until blended. Add the butter and pulse 8-10 times until the mixture forms large, coarse crumbs the size of small peas. Remove 2 cups of the crumb mixture and set aside. Press the remaining crumb mixture into the bottom and 1 inch up the sides of the pan. Drop teaspoons of the jam evenly over the crust, spreading gently with the back of the spoon to cover the crust. Sprinkle the reserved crumbs evenly over the jam layer.

Bake until the top is lightly browned, 50-55 minutes. Transfer to a rack and let cool until firm, about 2 hours. Using a sharp knife, cut into squares. Store in an airtight container at room temperature for up to 3 days.