Make the pecans: Mix the sugar and salt in a bowl and set aside.
In a small pot, melt the vegan buttery spread over medium low heat. Add the pecans and stir for a few minutes until they are toasted and coated in butter.
Using a slotted spoon, transfer the buttered pecans to the sugar mixture and toss to coat. Spread the pecans on a plate or cookie sheet to cool.
Make the sauce: Put the sugar, cocoa powder, and sea salt in a sauce pan and whisk together. Add the ½ cup of non-dairy milk and whisk. Heat the mixture over medium heat until it starts to simmer, then reduce heat to low.
Add the vegan buttery spread and the chocolate chips and stir until melted.
Put the arrowroot powder and the 2 Tablespoons of non-dairy milk in a small container with a lid. Shake well to remove lumps. Drizzle this mixture into the pan and stir constantly until thickened.
Remove pan from heat and add the coconut rum. Stir and place back on heat to thicken again if needed. Let cool for a few minutes.
Scoop ice cream into sundae cups and top with warm fudge sauce and pecans. Enjoy!