Merchie started better on the snow-laden surface and took the lead when Kai Bailey beat two men before netting from close range,
Not to be outdone, his strike partner Arin Tuncay quickly added two goals of his own – one a long-range strike and the other a shot in off the upright – to put Merchie in a commanding position.
With the half almost over, Merchie added another to further stretch the winning margin when Mackenzie Robertson converted from inside the box.
After the break, Cramond were unlucky not to pull at least a goal back with an improved display, but Merchie showed the importance of finishing opportunities as they bagged a fifth through Christian Robertson.
• Musselburgh Windsor 17s progressed to the semi-finals of the South East Region Cup with a 3-0 win over Tynecastle 17s at Pinkie Playing Fields.
Tynie began the stronger of the two sides and probably should have been ahead early on, but keeper Grant Goodfellow in the Mussie goal made a handful of good stops to deny them an early lead.
Mussy gradually settled into the game and they took the lead midway through the first half. A mix-up at the heart of the Tynie defence allowed Lewis Kynoch to intercept the ball and score.
It was a precarious lead and Tynie showed determination to get back into the game. However, Scott Brown gave Mussy a bit of breathing space with a scorching goal from 30 yards out.
Musselburgh then went on to safeguard their lead in the second half with their third and final goal. Liam Mitchell pounced at the back-post with a header that looped into the opposite corner for 3-0.
They now go on to play Airdrie United BC 17s in the last four of the competition.
• Tynecastle 19s secured a semi-final spot in the Bob Bankier Trophy with a 2-1 win over Leith Athletic YFC 19s at Meadowbank.
It was a fairly even start to the cup tie, but it was Tynie that went ahead just past the half hour mark, Jack Cowan nodding in after a fine cross from the left.
After the break Tynie then handed Leith a route back into the game from out of nowhere when a back-pass from captain Jack Philp from distance inadvertently made its way into his own net.
It didn’t deter Tynie’s focus, though, and they pressed on as the half progressed, eventually taking the lead again with 20 minutes to go. After some patient build-up play, the ball was worked to Danny Cameron in the box and he stuck his effort away to make it 2-1.
Late on both sides had chances to change the scoreline, the best of which fell to Tynie’s Dominic Foulkes, but he struck the post as his team held on for a narrow win.
They now go on to a tricky away against Loanhead MYFC 19s in the next round.