And then finally, just as they're running out of time, someone takes out the marshmallow, and then they gingerly put it on top, and then they stand back, and -- ta-da! -- they admire their work.
y, finalmente,  justo cuando se acaba el tiempo alguien saca el malvavisco, y con cautela lo coloca encima, y entonces se apartan, y "Ta-da!" admiran su trabajo