Chop and pit the Medjool dates, then combine with water in a medium pot. Simmer for about 5 minutes until softened, then mash until smooth.

Preheat the oven to 350°F (175°C) and grease an 8-inch square baking dish.

Cream together the softened butter and dark brown sugar until light and fluffy. Add eggs one at a time, mixing well after each. Fold in flour and baking powder, then mix in the mashed date mixture.

Pour the batter into the greased baking dish and bake for approximately 35 minutes, until the top is firm and golden brown.

Prepare the toffee sauce by combining cream, brown sugar, butter, and vanilla in a small saucepan over low heat, stirring until melted and bubbly.

Cut the pudding into squares, drizzle with warm toffee sauce, and serve immediately.