01 -
Preheat oven to 350°F (175°C). Line an 8x8 inch baking pan with parchment paper.
02 -
In a large bowl, whisk together flour, powdered sugar, and salt. Cut in the cold butter using a pastry cutter or your fingertips until the mixture resembles coarse crumbs. Press the crumb mixture evenly into the bottom of the prepared pan. Bake for 10-12 minutes, or until lightly golden brown.
03 -
In a separate bowl, beat together the softened cream cheese and sugar until smooth. Beat in the egg and vanilla extract until well combined. Stir in the sour cream until just incorporated.
04 -
Spread the cheesecake filling over the cooled crust. Top with the fresh blueberries.
05 -
In a medium bowl, whisk together flour, oats (if using), brown sugar, cinnamon, and salt. Cut in the cold butter using a pastry cutter or your fingertips until the mixture resembles coarse crumbs. Sprinkle the crumble topping evenly over the blueberries.
06 -
Bake for 35-40 minutes, or until the edges are golden brown and the center is slightly set.
07 -
Let the bars cool completely in the pan on a wire rack. Then, refrigerate for at least 2 hours, or until chilled and firm.
08 -
Cut into squares and serve.