Preheat the oven to 180C/160C Fan. Lightly grease your baking dish with butter and line with baking parchment.
Place the dates, boiling water and bicarbonate of soda into a bowl. Stir to combine and leave for 10 minutes.
In a stand mixer/ mixing bowl, mix the butter and black treacle together into a paste.
Add in the eggs one at a time, making sure each one is fully beaten into the mixture before adding the next one.
now add in the flour, pumpkin spice and baking powder, making sure to mix these into the batter on a lower setting/more gently.
Your dates should be softened by now! Press them gently in the liquid and mix around. You should have a liquid-y paste of water and dates.
Add the date and water mixture into the cake batter, and combine gently.
Scrap this mixture into your baking dish. Bake for 35 minutes.
while you are waiting for the cake to bake, time to make the toffee sauce!
Melt the butter, muscovado sugar and treacle over low heat in a pan, making sure to keep stirring throughout. The butter should melt first, keep on stirring until everything else has as well.
Now turn up the heat to medium, and stir in the cream. Keep stirring until the mixture is a caramel-goden colour and is bubbling. Take of the heat and pour into a jug.
Once your cake is done, check that it is baked all the way through by poking it in the middle with a knife or skewer. If the instrument comes out clean, it is done!
While the cake is piping hot, pour roughly a quarter of the sauce on top of the cake. it will absorb into the cake as it cools, making it moist and sticky. Let the cake cool for about 10 minutes.
You are done! Eat hot with cold ice cream or cream, and drenched in the toffee sauce. Enjoy!