In a small saucepan, combine all the filling ingredients. Cook over low heat for 5 to 7 minutes, until thickened. Set aside for 10 to 15 minutes to allow the dates to soften fully.
Preheat the oven to 350 degrees F.
To make the crust, mix together the oats, flour, brown sugar, and soda. With a fork, blend the butter into the oat mixture. Divide in half and press half into the bottom of an ungreased 9-inch by 13-inch baking pan. Spread the date filling on top. Sprinkle with the remaining oat mixture.
Bake for 30 minutes. Cool completely before cutting into squares.