Line two baking sheets with aluminum foil, then place a wire cooling rack on top of each baking sheet.

Mix together the baking powder, paprika, black pepper, and salt in a small bowl.

Place raw wings into a large Ziplock bag, then sprinkle the spice rub over the wings. Seal the bag and shake so all wings are evenly coated with the spice rub.

Remove wings from bag and place on the wire racks, leaving a little room between each wing.

Refrigerate the baking sheets with the wings, uncovered, for 12-24 hours (overnight is best).

Whisk together the soy sauce and the cornstarch in a small bowl.

Combine the maple BBQ sauce, honey, brown sugar, and onion powder into a small saucepan, then whisk in the soy sauce/cornstarch slurry until all ingredients are combined.

Heat the Firehouse BBQ sauce over medium-high heat, stirring regularly, until boiling. Then reduce the heat to low and simmer until the sauce is thickened, about 10 minutes. Remove sauce from heat and set aside.

Preheat your grill to 300F. Place chicken wings on the grate, close together but still leaving breathing room between each wing, and grill 30 minutes until cooked through, flipping the wings every 5 minutes.

Remove wings from the grill (but leave the grill on!) and pile them into a heat-proof bowl. Pour the homemade Firehouse BBQ sauce over the wings and toss with tongs until all the wings are coated.

Use your tongs to place the saucy wings back on the grill. Cook wings another 5-10 minutes, flipping once or twice, until the sauce has caramelized and the wings are lightly charred.

Remove wings from grill (you can turn it off now!) and pile onto a platter. Serve immediately with LOTS of napkins.