Place the coconut milk in a small saucepan over medium heat. Whisk until well emulsified and bring to a small boil. Add in the agar, salt and agave and whisk for about 2 minutes. Add in the lecithin, whisk again, and remove from the heat.
Pour into ramekins with lids or custard cups (grease with a little cooking spray or brush with oil first) and place in the refrigerator to gel overnight.
To serve, slide a knife around the panna cotta, then place a plate on top of it. Flip it upside-down to release the panna cotta onto the plate.
In a small cast-iron pan, heat the vegan butter and brown sugar over medium-low heat until it starts to slightly caramelize. Drizzle the sauce over the panna cotta and serve immediately.
