Preheat the oven to 350 F (177 C). Grease and line the bottom of a 9- inch (23 cm) springform or 8 inch cake pan with parchment paper.
Place pitted and chopped dates into a medium bowl. Top the dates with baking soda. Gently toss the dates to cover with baking soda. Pour boiling water or milk over the dates, cover with a tea towel and allow the dates to soak for about 10 - 15 minutes. Pour the date and milk mixture into a stand mixer fitted with paddle attachment. Mix the dates and milk together until a loose paste forms. For a smoother date paste pour the dates and milk into a blender or food processor. Once the paste is created, return the date paste back to the same bowl and set aside for now. Wipe the mixing bowl to remove any significant date paste residue. 2 cups (9 oz.) pitted Medjool dates, 1¼ cup (300 ml) boiling milk or water , 1 teaspoon baking soda
In a large bowl, whisk together the flour, baking powder, cinnamon and salt together until well combined. Set aside for now.
1½ cups (180 g) all purpose flour, 1 teaspoon baking powder, 1 teaspoon ground cinnamon, optional, ¼ teaspoon salt
In a large mixing bowl fitted with paddle attachment, cream the butter and light brown sugar together on medium speed for 2 - 3 minutes until well combined. With the mixer on low, cream in the date paste followed by the eggs and vanilla extract.
½ cup (113 g) unsalted butter, room temperature, ½ cup (100 g) light brown sugar, 2 large eggs, room temperature, 1½ teaspoons vanilla extract
Once the date paste, eggs and vanilla extract are fully mixed in, increase the mixer speed to medium for another minute. Scrape the bottom and sides of the bowl as needed. With the mixer on low, mix in the dry ingredients into the wet until just combined.
Evenly pour the brown sugar date cake batter into the prepared pan. Bake the sticky date cake for 30- 35 minutes or until a toothpick inserted into the center of the cake comes out clean or with a few moist crumbs. The crust will be golden brown and the top should bounce back when gently pressed. Cool the cake in the pan for 30 minutes. While the cake cools, make the toffee sauce. Add the slices of butter, heavy cream and brown sugar to a saucepan. Heat the mixture to a boil over medium-high heat. Stir and simmer the mixture for about 2-3 minutes. Remove the pan from the heat, stir in the salt and vanilla extract. The sauce will thicken a bit while it cools.
4 tablespoons (57 g) unsalted butter, ⅔ cup (160 ml) heavy cream, ½ cup (100 g) light brown sugar, 1 teaspoon vanilla extract , ¼ teaspoon salt
While the cake is still warm, use a toothpick, tines on a fork or skewer to poke lots of holes in the top of the cake. Pour about ½ of the toffee sauce on top of the cake. If you would like, use the back of a spoon or a pastry brush to push the sauce into the cake. Allow the cake to cool and soak in the toffee sauce for another 20 - 30 minutes. Release the sides of the pan from the cake, or lift the cake out of the pan using the parchment paper. Transfer the cake to a serving plate, top with more toffee sauce if you like.Serve the sticky date cake with more toffee sauce and ice cream.