Step 1In a large heavy-bottom saucepan, combine the cream, butter, brown sugar and maple syrup. Bring to a boil over high heat, whisking frequently. After the mixture comes to a boil, remove from heat. Blend the mixture using an immersion blender until thickened and emulsified. Alternatively, the mixture can be blended in batches using a standard blender (be careful as the mixture is very hot). This makes 4 cups sauce.
Step 1Heat the oven to 350 degrees. Grease 6 (6-ounce) ramekins with butter, and dust with sugar. In a saucepan, whisk the baking soda into the boiling water.
Step 2In a large bowl, whisk together the flour, salt and baking powder.
Step 3In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl using an electric mixer, beat the butter, brown sugar and vanilla until fully incorporated.
Step 4To the butter mixture, add the egg and beat until fully incorporated. Over low speed, slowly and gently add the dry ingredients, scraping the bowl to make sure the batter is fully mixed.
Step 5Over low speed, slowly stream the hot water into the batter. Add the dates and continue mixing over low speed until the batter thickens. This makes about 2 cups batter.
Step 6Divide the batter between the prepared ramekins. Bake until the cakes are a dark, caramel color, about 45 minutes.
Step 7Remove the ramekins and cool the cakes for 5 minutes, then invert the cakes onto a rack over a rimmed baking sheet. Pour the hot toffee sauce onto the cakes until they seem saturated (extra sauce will pool at the bottom, this can be gathered for additional glazing and serving), then glaze the cakes a second time with the sauce.
Step 8Set the cakes aside for about 30 minutes to set up and cool. The cakes can be made a few hours in advance and held on a baking sheet, loosely covered with plastic wrap, at room temperature.
Step 9To serve, cover each cake with one-fourth cup warm toffee sauce. Serve with a generous quenelle or dollop of mascarpone cream or whipped cream, or scoop of ice cream.