Preheat oven to 350°F. Line a baking sheet with parchment paper.
Lay bacon slices flat on the prepared sheet. Brush both sides with 2 tablespoons maple syrup.
Bake for 20 to 25 minutes, flipping halfway, until crisp and sticky. Transfer bacon to paper towels.
Slice Hawaiian rolls in half horizontally, keeping tops and bottoms connected.
Place bottom half of rolls in a 9x13-inch baking dish.
Layer brie slices evenly over bottom rolls.
Chop bacon into bite-sized pieces. Spread over brie layer.
Sprinkle toasted chopped pecans evenly over bacon.
Place top half of rolls over filling.
In a small bowl, whisk together melted butter, 1 tablespoon maple syrup, garlic powder, and flaky salt.
Brush mixture generously over tops of rolls.
Cover baking dish loosely with foil. Bake for 15 minutes.
Remove foil. Bake an additional 7 to 10 minutes, until cheese is melted and tops are golden brown.
Remove from oven and let sliders rest 5 minutes before slicing and serving.