PREHEAT oven to 400° F. Grease 8-inch-square baking pan.
COMBINE dates, evaporated milk, sugar and vanilla extract in medium saucepan. Cook, over medium-low heat, stirring occasionally, for 8 to 10 minutes or until thickened. Remove from heat.
BEAT butter and brown sugar in large mixer bowl until creamy. Beat in flour, oats, baking soda, salt and cinnamon. With floured fingers, press half of crust mixture onto bottom of prepared baking pan. Spread date filling over crust. Top with remaining crust.
BAKE for 20 to 25 minutes or until golden. Serve warm.