Next level sticky toffee pudding

Name: Next level sticky toffee pudding
Ingredients: 200g butter, softened, plus extra for the tin; 300g stoned dates (prepared weight); 1 tsp bicarbonate of soda; 1 tsp vanilla extract; 100ml dark rum (optional); 100g pecans, broken into large chunks or roughly chopped; 225g light muscovado sugar; 4 eggs; 225g self-raising flour; 1 tsp mixed spice; 1 tsp ground ginger; vanilla ice cream, double cream or clotted cream, to serve; 150g light muscovado sugar; 50g butter; 1 tbsp treacle; 200ml double cream