Preparation: Start by preheating your oven to 350°F. Line a 9x13 inch baking pan with parchment paper or generously grease it with non-stick cooking spray for easy removal and cutting of the bars after baking.

Crust and Crumble: In a large bowl, blend the softened butter, granulated sugar, and brown sugar until the mixture is light and fluffy. Add in the salt and baking soda. Gradually incorporate the all-purpose flour and quick oats, mixing until the texture becomes crumbly. Press half of this crumbly mixture firmly and evenly into the bottom of your prepared pan. Bake in the preheated oven for about 13 minutes until set and slightly golden.

Cream Cheese Filling: While the base is baking, prepare the filling. In another bowl, beat the cream cheese until it’s smooth and free of lumps. Slowly add the sweetened condensed milk, mixing until fully combined. Stir in the vanilla extract and egg yolk, ensuring everything is well-blended.

Assembly: Take the partially baked crust out of the oven. Pour the cream cheese mixture over the crust and spread it evenly. Sprinkle the blueberries over the cream cheese layer. Crumble the remaining oat mixture over the blueberries and gently press it down to form the top layer.

Final Baking: Place the pan back in the oven and bake for an additional 20-25 minutes, or until the edges are golden and the top is firm.

Cooling and Cutting: Once baked, remove the pan from the oven and let the bars cool completely in the pan on a wire rack. After cooling, use the parchment paper edges to lift the bars out of the pan. Place them on a cutting board and cut into desired sizes.

Storage: Store the cut bars in an airtight container, with parchment paper between layers to prevent sticking. Refrigerate for up to five days or freeze for longer storage.