Heat a sauté pan over medium heat. Add oil and plantain rounds. Sprinkle with garlic powder, sea salt, pepper and drizzle with brown rice syrup. Cook about 3-5 minutes per side, until golden and soft in middle. Remove from heat.
Spread 2 slices of bread with black bean spread and spread other 2 slices with vegan mayonnaise. Top the black bean spread with plantains and 1 ½ slices GO Veggie! Dairy Free Pepper Jack Sliced Cheese. Top with the 2 slices of bread with vegan mayonnaise to enclose.
Heat a flat pan or griddle over medium heat and add buttery spread. Add sandwiches to pan and grill for about 3 minutes per side, or until golden and cheese is melted.
Top with additional grilled plantains if desired.