Grease the slow cooker and line with baking paper. Put the dates and bicarbonate of soda into a heatproof bowl. Pour over
Using an electric mixer, beat the butter, sugar and maple syrup until thick and pale. Beat in the oil, then add the eggs one at a time, beating well after each addition. Gently fold in the date mixture, followed by the flour, until just combined. Spoon into the slow cooker and cook on low for 3 hours.
To make the caramel sauce, put the maple syrup and sugar into a small saucepan over medium heat, stirring until dissolved. Add the butter and salt, stirring to melt. Once the butter has melted, reduce the heat to low and cook for 5 minutes until thickened slightly.
Carefully remove the pudding and serve with the caramel sauce and ice cream.