Preheat oven to 350°F.
Butter 8x8-inch baking pan. In medium saucepan bring 1 1/2 cups water to a boil. Reduce heat to simmer. Add chopped dates and simmer until thick, stirring fequently for approx 10 minutes. Cool to room temperature. Stir in vanilla.
In separate bowl combine flour, sugar, oats, cinnamon, baking soda, and salt. Using hands, add butter chunks until crumbles form. Press 1/2 of flour mixture in bottom of prepared pan. Spread date mixture over. Sprinkle with remaining flour mixture; press down gently. Bake until edges are golden and center is set, approx 40 minutes. Cool completely in pan on rack. Cut into bars and serve.