Place the dates and bicarbonate of soda in a heatproof bowl and pour boiling water over them. Allow to stand, uncovered, for 20 minutes or until the dates are tender.
Using an electric mixer, beat the butter, sugar and vanilla until pale and creamy. Add the eggs, one at a time, beating well after adding each egg. Using a large metal spoon. Stir in the date mixture and flour. Mix until well combined.
Spoon the mixture into the rice cooker. Close the lid and turn the handle to the lock position. Press the “Menu” button to select the “Cake” function (for the M10, use the “Multicook” function). Press “Start/Cook”To ensure it’s cooked through (around 45 minutes for the M10), make sure a skewer instead into the center comes out clean. Let the cake stand for 10 minutes before turning it out into a wire rack.
To make the coconut sauce: put all the ingredients for the sauce into the rice cooker after taking out the cake. Press the “Menu” button to select the “Multicook” function and heat until the sauce thickens to the desired consistency.
Pour the warm sauce over the warm cake. Cut into wedges and serve.