Preheat oven to 350 degrees.
Lightly oil six 1/2 cup ramekins or one smallish 3 cup cake tin.
In a small saucepan, heat the coffee or water over high heat until it just comes to boil. Turn off the heat, but leave the pot on the burner. Drop in the dates and let them soften and rehydrate for 15 to 20 minutes.
Pour dates and the coffee or water they’ve been soaking in into a food processor or blender. Whizz them until they form a smooth puree. Add the plant-based butter, and whizz again until mixture is thick and luscious.
Add the flour, baking powder, baking soda, brown sugar, whiskey and seltzer. Give everything one quick blast together until it forms a smooth, syruppy batter.
Spoon batter into ramekins or cake tin. Baking time will be 20 minutes for the ramekins, closer to 30 minutes to the cake tin. Cake is done when golden-brown and tender. Allow to cool before unmolding.
Meanwhile, make the caramel sauce.
Pour coconut milk into a deep saucepan. Heat saucepan over medium-high heat. Stir in brown sugar until it dissolves. When mixture starts to bubble, reduce heat to medium-low, and continue to cook for 20 minutes or so. Sauce will thicken and darken. Stir occasionally to prevent sticking and spatter.
When sauce is thick and the color of cafe au lait, and the whole kitchen smells of caramel, turn off burner. Stir in pinch of sea salt and half teaspoon whiskey.
Allow sauce to cool slightly, then lavish cake with it and enjoy.