Calypso Bars

1 ⅓ cups chopped dates

2 ½ (1 ounce) squares unsweetened chocolate

⅔ cup water

1 ⅓ cups white sugar

¼ cup butter

1 teaspoon vanilla extract

1 ¼ cups packed brown sugar

¾ cup butter

1 ½ cups quick-cooking oats

1 ½ cups all-purpose flour

1 cup chopped walnuts

½ teaspoon baking soda

½ teaspoon salt

Preheat oven to 350 degrees F (175 degrees C). Grease an 8x10-inch baking pan.

Cook and stir dates, chocolate, water, white sugar, and 1/4 cup butter in a heavy saucepan over medium-low heat until melted and thickened, 5 to 10 minutes. Remove from heat; stir in vanilla extract. Set aside to cool.

Beat brown sugar and 3/4 cup butter together in a bowl until creamy. Add oats, flour, walnuts, baking soda, and salt; stir until texture is crumbly.

Press half the oat mixture into bottom of the prepared pan. Evenly spread chocolate-date mixture over oat mixture layer; crumble remaining oat mixture over chocolate-date layer.

Bake in the preheated oven until topping is lightly browned, about 30 minutes. Cut into 30 small squares.