Preheat oven to 325 degrees. Butter 4 4-inch round ramekins. Sift the flour and baking powder onto wax paper. Place chopped dates in a small bowl and add the boiling water and baking soda; set aside. In another bowl, beat the butter and sugar until light and fluffy. Add the egg and vanilla and beat until blended. Slowly beat in the flour and baking powder. Add the date mixture to the batter and fold until blended. Pour into the ramekins. Bake until pudding is set and firm on top, about 25 minutes. Remove from oven and place on a wire rack.
Combine the butter, half and half and brown sugar in a small saucepan. Heat to boiling, stirring constantly. Simmer over medium low heat for about 8 minutes until thickened.
To serve, invert pudding into a bowl. Place a heaping scoop of your favorite vanilla ice cream into the bowl and drizzle all with the toffee sauce.