Ensure your bananas are peeled, sliced, and frozen solid (at least 6 hours or overnight). If using full-fat canned coconut milk, chill the can overnight in the refrigerator; this helps the cream separate from the liquid, allowing you to easily scoop out the thick cream.

In a high-speed blender, combine the frozen banana slices, 1 cup of the chilled full-fat coconut milk (or heavy cream), maple syrup (if using), vanilla extract, and sea salt.

Blend on high speed, scraping down the sides of the blender with a spatula as needed, until the mixture is completely smooth and creamy. The consistency should be thick but pourable, resembling a luscious, velvety soup. If it's too thick, add the remaining 1/2 cup of coconut milk gradually, blending until you reach your desired soup-like consistency.

Taste the banana 'ice cream' soup and add more maple syrup if desired for extra sweetness, or a tiny pinch more salt to enhance the flavors. Blend briefly to incorporate any additions.

Pour the banana soup into a large bowl or individual serving bowls. Cover them tightly and refrigerate for at least 3 hours to allow the soup to chill completely and for the flavors to meld beautifully. For an even thicker, almost soft-serve consistency, you can briefly place the covered soup in the freezer for about 30-45 minutes before serving, stirring it halfway through.

Once thoroughly chilled, ladle the velvety banana 'ice cream' soup into individual bowls. Garnish with your favorite toppings such as fresh berries, toasted coconut flakes, a drizzle of chocolate, or chopped nuts. Serve immediately and enjoy this unique dessert soup!