Jonatan Giraldez's side are into the final against Huesca after a four-goal win over rivals Madrid
Barcelona hammered Real Madrid 4-0 on Wednesday to set up a Copa de la Reina final against Sporting Huelva this weekend.
Lieke Martens, Aitana Bonmati, Mariona Caldentey and Asisat Oshoala got the goals as Barca recovered from the Champions League final defeat to Lyon in the best possible way.
Alexia Putellas and Oshoala his the woodwork early on before Martens opened the scoring in the 18th minute, capping a fine team move.
Barça had to wait until the second half for more goals, but the result was never really in doubt as they beat Madrid for the sixth time this season.
Bonmati added the second, taking a clever touch before sliding home after good work from Oshoala, whose initial effort had been blocked.
Caldentey then added the third from a corner before Oshoala finally got in on the act, racing in behind the Madrid defence, rounding goalkeeper Misa Rodriguez and rolling home.
Barça will meet Huelva in the final on Sunday with a domestic treble still on the table following their success in the Primera Division and the Spanish Supercopa.