Step 1

Preheat oven to 180°C/350°F. Grease a deep 20cm (8-inch) round cake pan; line base and side with baking paper.

Step 2

Combine dates and the water in a medium heatproof bowl. Stir in soda; stand 5 minutes.

Step 3

Blend or process date mixture with butter and sugar until smooth. Add eggs and flour; blend or process until just combined. Pour mixture into pan.

Step 4

Bake cake 1 hour. Stand cake in pan 10 minutes before turning onto a serving plate.

Step 5

Meanwhile, stir butterscotch sauce ingredients in a medium saucepan over low heat until smooth.

Step 6

Serve cake warm with butterscotch sauce.