Place the dates in a bowl, pour over the boiling water, and stir in the baking soda. Let the mixture soften for 15 minutes, then mash it into a thick, textured puree.
Preheat the oven to 350 F and grease an 8-inch square baking dish. Beat the plant butter and brown sugar until fluffy, then beat in the eggs one at a time and add the vanilla.
Whisk the flour, baking powder, and salt in a separate bowl. Fold the dry ingredients and softened date mixture into the butter mixture just until evenly combined.
Spread the batter in the prepared dish and bake for 30 to 35 minutes, until the center springs back when gently pressed. Let the cake rest for 10 minutes.
Combine the plant butter, brown sugar, coconut cream, vanilla, and salt in a saucepan. Simmer over medium-low heat for 4 to 5 minutes, stirring frequently, until glossy and slightly thickened.
Poke deep holes across the warm cake with a skewer and slowly pour one-third of the toffee sauce over the top. Let the sauce soak in for 10 minutes.
Serve the sticky date cake warm with the remaining toffee sauce spooned generously over each portion.