Preheat the oven to 180ºC / 350ºF.
Line a 8 x 8″ pan with baking paper.
Soak the dates in a bowl of boiling water for 5 minutes. Strain, add to a food processor and mix to form a date paste. Set aside.
To make the crumble, in a food processor, add the flour, oats, sugar and margarine until crumbs form. Do not overmix.
Transfer half into the baking tin and press down with your fingers to create the first layer.
Spread the date paste evenly on top of the first layer.
Sprinkle the remaining crumble on top of the second layer to create the final layer of the date crumble.
Place in the oven and bake for about 40 minutes until golden.
Remove from oven and allow to cool for about 20 minutes before serving.