Over medium heat in a large pot add the butter and brown sugar, whisk constantly for 3-4 minutes. Once the butter has melted slowly add one tablespoon of cream at a time. Let the mixture come to a roaring boil for 2-3 minutes.
Make Sticky Toffee Sauce
In a large heatproof bowl add the dates and hot water, let the mixture sit for 10 minutes, this helps soften the dates.
Add the softened butter and sugar, mix on medium speed for 2-4 minutes, until light and fluffy. Don't forget to scrape down the sides of the bowl.
Cream the Butter and Sugar
Add the eggs one at a time, making sure to fully mix after each addition, again scraping the sides of the bowl.
Add the Eggs
In a small bowl whisk together the flour, baking powder, and salt.
Whisk the Dry Ingredients
In a food processor add the dates and liquid add baking soda and pulse 8-10 times until the mixture has broken down mostly- there will still be chunks that's what you want.
Gently fold half of the dry ingredients into the wet mixture. Add half of the date mixture. Next, add the rest of the dry ingredients and the date mixture again. Pour half of the batter into the prepared pan.
Spoon 5-6 teaspoons of the sticky toffee sauce on top of the batter and use a butter knife to swirl the sauce into the batter. Repeat then bake.
Reheat the remaining sticky toffee sauce just for a few seconds to loosen it, and use the remaining sauce to drizzle on top of the cake.