Preheat oven to 400°F (200°C). Grease a 9"x 13" pan. If you prefer, you can also line the pan with parchment paper, and grease the paper.
Whisk together the flour, salt, and baking soda. Stir in the oats. Set aside.
Using an electric mixer on medium speed, beat the butter and brown sugar until light and fluffy.
Reduce mixer speed to low. Gradually add the flour mixture, mixing just until combined. The mixture will be crumbly but should hold together when pinched.
Set aside half of the crust mixture.
Transfer the remaining crust mixture to the prepared pan, and press evenly into the bottom of the pan.
Spread the raspberry preserves on top of the crust.
Sprinkle the remaining crust mixture on top of the preserves.
Bake 18 to 20 minutes, or until golden brown and the filling is bubbly.
Cool the bars in the pan on a wire rack. Cut into bars for serving.
Notes
Recipe slightly adapted from Southern Living.
Store in an airtight container at room temperature up to 5 days.