Place the 4 tablespoons of butter in a microwave-safe, medium-size bowl and heat for 45-60 seconds on high power or until melted. Set aside to cool for 5 minutes. Preheat the oven to 375ºF and generously butter a baking dish that will hold 6-8 cups. Place the buttered pan on a sheet pan.

In a medium-size bowl, whisk together the melted butter and brown sugar. Add the egg and vanilla extract and whisk until the egg is incorporated, then add the half and half (or milk) and stir until well-combined.

Sprinkle the flour, baking powder, salt over the top and stir until smooth. Fold in the chopped dates. Transfer the batter to the prepared pan and spread to an even layer. (It won’t look that full yet but have no fear, it will be perfect by the time it’s done!)

Sprinkle the brown sugar over the top of the batter and dot with the small pieces of butter. Pour the boiling water over all of this (I know, sounds so strange!) and transfer the pan (with the sheet pan underneath) to the oven. Bake for 35-40 minutes or until the top of the cake springs back when lightly touched.

Serve warm. Scoop the cake and sauce (underneath the cake there will be a rich, sticky sauce) into dessert bowls. Serve with vanilla ice cream.