Grease an ovenproof dish (approx. 20 x 30cm) with butter and preheat the oven to 180C/160C Fan/Gas 4.
Put the dates and bread soda in a bowl. Pour over the boiled water and set aside.
In a seperate mixing bowl, beat the butter and sugars together until light and fluffy.
Add the eggs and beat until just incorporated.
Sieve the flour into the bowl and fold in gently.
Add the dates and the water. Stir gently until evenly distributed, then pour the mixture into the prepared dish.
Bake in the preheated oven for 25-30 minutes, until it is springy to the touch.
To make the sauce, add all of the ingredients to a saucepan and cook over a low heat until the butter has melted and the sugars have fully dissolved. Bring to the boil, then reduce the heat and simmer until the sauce has thickened to a pourable consistency.
Remove the sponge from the oven. Using a skewer poke holes in the top while it is still warm and pour over half the sauce. Set aside, allowing time for the sponge to absorb the sauce.
When ready to serve, warm the sticky toffee pudding and serve with the rest of the sauce (also warmed through). Delicious served with fresh cream or ice cream.