For the vanilla ice cream, in a heatproof bowl, mix together the cream, milk and vanilla seeds. Place the bowl over a pan of simmering water (do not allow the base of the bowl to touch the water). Heat the mixture gently but do not boil.
Meanwhile, beat the egg yolks and sugar until fluffy. Add the cream mixture to the eggs and stir well.
Return to the heated bowl and cook gently over the simmering water, stirring regularly, until the mixture is thick enough to coat the back of a spoon. Set aside to cool.
Churn in an ice cream maker for approximately 40 minutes, or following the manufacturer's instructions until set.
For the sticky toffee pudding, preheat the oven to 190C/170C Fan/Gas 5. Grease a 20cm/8in square cake tin with butter and dust with flour.
Blend the butter and sugar together in a freestanding mixer with a whisk attachment or using a hand-held whisk.
Gradually add the golden syrup, treacle, vanilla and eggs and mix thoroughly. Turn the mixer down to a slow speed and add the flour. Once all the ingredients are combined, turn off the mixer.
Place the dates and 300ml/10fl oz water in a saucepan and bring to the boil.
Allow to cool slightly, then use a blender to purée the date mixture. Add the bicarbonate of soda. Quickly stir this into the batter while it is still hot.
Pour into the prepared cake tin and bake for 40-45 minutes, or until the top is firm to the touch. Leave the pudding to cool in the tin.
For the butterscotch sauce, in a small saucepan heat the butter, brown sugar and golden syrup until combined and the sugar is dissolved. Bring to a gentle simmer, then remove from the heat and add the lemon juice to taste. Stir in the double cream.
Serve slices of pudding with ice cream and sauce poured over.