Heat your oven to 350F and spray the bottom of an 8X8 or 9X9 square baking pan with vegetable cooking spray.
In a large microwave-safe mixing bowl combine the chocolate chips and margarine. Heat for about 30 seconds until the chocolate begins to melt. Stir and return to the microwave for another 15 seconds. Stir and repeat until the chocolate is melted.
Add the flax egg, vanilla, plant-based milk, and brown sugar. Stir until well combined.
In a separate bowl stir together the flour and salt. Pour the flour mixture into the chocolate mixture and stir until just combined. You don't want to overmix this step.
Spread the brownie layer into your prepared baking pan. Place in the oven and bake for about 15 minutes.
In the meantime, prepare your Sweetened Almond Condensed Milk by combing the almond milk, corn starch, and sugar in a large, microwave-safe bowl. Stir until there aren't any lumps from the corn starch. Microwave for about a minute and stir. Repeat this until the mixture is nice and thick, usually about 3 minutes. Then add the vanilla and give it one more stir to combine. Set aside until the brownies are ready.
After 15 minutes of baking, remove the brownies from the oven, top with the Sweetened Almond Condensed Milk, and top that with the coconut, chocolate chips, and chopped walnuts. Return the brownies to the oven and bake for another 10-15 minutes.