Reigning champions Wolfsburg will now bid to retain their title, hoping to claim it for the third time in four seasons, whereas Sand will be looking to lift the trophy for the first time in their history.
Bayern falter in last four
Coming into today's games, the only thing expected to come was a mouth-watering final between Bayern and Wolfsburg, the current top two in the league.
However, it was not to be as Sand scored an 84th minute winner to eliminate the leaders and pave their own way to the final - Anne van Bonn the heroine late on.
Things looked to be following the script in the first half when Vivianne Miedema put Bayern one up on the road, but the hosts dusted themselves off and came out determined in the second period.
Within 16 minutes, they were level through Jovana Damnjanović, and then their persistence late into the game paid off too as van Bonn's fifth of the competition ensured their unlikely passage to the final.
Bayern may seem to have the league title in the bag, but it will be the only silverware they pick-up this season after today's defeat and elimination from the UEFA Women's Champions League in the first round. Sand, meanwhile, get a rare crack at glory as they continue an impressive campaign.
Wolves follow the script
After Bayern had slipped up in the earlier of the two games, Wolfsburg instead kept their cool as they saw off Freiburg by a 2-1 score.
Alexandra Popp settled any early nerves with her opener on five minutes, and Babett Peter popped up with a late goal deep into the second half to round things off.
Giulia Gwinn did manage to give the Wolves a bit of a scare late on, striking home in the 89th minute to give Freiburg a glimmer of hope, but it was too little too late as Breisgau-Brasilianer bowed out of the competition.
It will be Sand - Wolfsburg in Cologne next month then, with the final to be played at the RheinEnergieStadion on Saturday 21 May.
Wolfsburg will obviously be the favourites, especially as holders, but Sand beat them 1-0 earlier in the season in the league and forced the Wolves to overcome an early 2-1 deficit to get revenge in the reverse recently.
With silverware at stake, it will by no means be an encounter that is easy to predict, with Sand to be given a rare opportunity to clinch a trophy and sure to be keen to take it.