Combine the dates, nuts, 1 teaspoon vanilla, and water in a medium saucepan. Place the pan over medium heat and bring to a boil; reduce heat to low and simmer until thickened, about 8 to 10 minutes, stirring frequently. Set aside to cool.

Preheat the oven to 350 F.

Lightly butter a 9-by-13-by-2-inch baking pan or spray the pan with baking spray.

In a mixing bowl with electric mixer, combine the flour, sugar, baking powder, salt, butter, 1 teaspoon vanilla, and egg. Mix until crumbly. Set aside 1 cup of the mixture and pat the remaining crumb mixture into the bottom or the prepared baking pan. Spoon date mixture evenly over the crust and spread gently to cover.

Sprinkle evenly with the remaining 1 cup of crumbs.

Bake for 30 to 35 minutes, or until browned.

Cool completely before cutting.