Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking pan.
In a medium bowl, mix together melted butter, brown sugar, oats, baking soda, salt, and vanilla. Press half of the mixture into the bottom of the prepared baking pan.
In a small bowl, mix together raspberry preserves and lemon juice. Spread over the crust in the pan.
In a medium bowl, mix together flour, white sugar, and remaining oat mixture. Sprinkle over raspberry layer.
Bake in preheated oven for 25 to 30 minutes, or until top is golden brown.
Interesting Facts
Lemon and raspberry are a classic flavor combination.
Oats are a great source of dietary fiber.
These bars can be stored in an airtight container for up to 4 days.