Saracens booked their place in the Aviva Premiership final thanks to a scrappy 12-10 win over Gloucester, with Owen Farrell kicking four penalties for the home side.
Saracens will have a chance to avenge last season's final defeat against Leicester.
In a repeat of the 2009/10 showpiece, the Watford-based outfit will need to improve if they are to avenge that loss as only a late kick from Farrell edged this semi-final.
But Saracens will argue they should have won by a bigger margin had it not been for the inaccuracy of their kickers.
Saracens started the brighter and they had the chance to open the scoring, but Richard Wigglesworth's penalty attempt was well wide of the right-hand upright.
The hosts continued to press and a wonderful break by winger James Short looked to have given them the lead. However, the Television Match Official ruled that his foot was in touch after Rory Lawson's superb cover tackle.
Having gone into the game on an 11-match winning streak, confidence was high in the Saracens camp and Gloucester initially struggled to live with their intensity.
But they were reprieved by two more missed penalties from Alex Goode and Owen Farrell. Visiting fly-half Nicky Robinson also failed to hit the target with his three-point attempt, but Farrell finally broke the deadlock after 16 minutes.
The pivot added another penalty to extend their lead to 6-0 before Robinson got his side on the scoreboard with one of his own. Farrell took advantage of more Gloucester ill-discipline straight after half-time.
With 17 minutes to go, the potential turning point. Lock Steve Borthwick was harshly sin-binned and just before he returned, Gloucester went the length of the field to score.
After Farrell's drop-goal attempt was charged down, the ball was moved wide. Full-back Freddie Burns then off-loaded to wing James Simpson-Daniel, who shipped it on to Robinson to touch down for a converted try.
But the burgeoning Farrell kept his cool to send Saracens to Twickenham.
Pens: Farrell 4
Saracens: 15 Alex Goode, 14 David Strettle, 13 Chris Wyles, 12 Brad Barritt, 11 James Short, 10 Owen Farrell, 9 Richard Wigglesworth, 8 Ernst Joubert, 7 Jacques Burger, 6 Kelly Brown, 5 Mouritz Botha, 4 Steve Borthwick (capt), 3 Carlos Nieto, 2 Schalk Brits, 1 Matt Stevens.
Replacements: 16 Jamie George, 17 Rhys Gill, 18 Petrus du Plessis, 19 Hugh Vyvyan, 20 Andy Saull, 21 Neil de Kock, 22 Nils Mordt, 23 Noah Cato.
Gloucester: 15 Freddie Burns, 14 Charlie Sharples, 13 Tim Molenaar, 12 Eliota Fuimaono-Sapolu, 11 James Simpson-Daniel, 10 Nicky Robinson, 9 Rory Lawson, 8 Luke Narraway (capt), 7 Akapusi Qera, 6 Alasdair Strokosch, 5 Alex Brown, 4 Jim Hamilton, 3 Paul Doran-Jones, 2 Scott Lawson, 1 Nick Wood.
Replacements: 16 Darren Dawidiuk, 17 Alasdair Dickinson, 18 Rupert Harden, 19 Dave Attwood, 20 Brett Deacon, 21 Dave Lewis, 22 Jonny May, 23 Tom Voyce.
Referee: Andrew Small