McInnes named an unchanged starting XI from the side that overcame St Mirren 2-1 in Paisley at the weekend.
The Dons welcomed visitors Dundee to Pittodrie for their third game in a week knowing that a victory would take them within one point of league leaders Rangers and level with Celtic. Dundee, on the other hand, came into the tie off the back of a 3-1 defeat to Kilmarnock, a game which ended their mini-revival after taking points off both Hibs and Rangers.
The home side started the game well, winning an early corner after some good perseverance down the right from the skipper. Cosgrove got up well from the resulting set-piece and nodded onto May who had his effort hooked off the line by Kenny Miller who was back defending.
Shinnie was getting on the ball frequently in the early stages and did well to win a free kick in a dangerous area 25 yards out from goal. Both May, Ferguson and McGinn all showed interest in it but it was the latter who struck and forced Dundee keeper Jack Hamilton into a routine save.
A goal was coming and it eventually did on the fifteen-minute mark. It came from a Dundee corner, within a flash The Dons were up the other end and it was 4 on 2 with red shirts piling forward to join McLennan. The winger picked out May but after May's shot was blocked the chance looked to have gone. But possession was well recycled and McLennan got a second chance to deliver and this time he put it on a plate for Sam Cosgrove who nodded home from close range to open the scoring. It was the third goal in as many games for the big striker.
Cosgrove was clearly oozing with confidence and The Dons looked in the mood to add to their tally.
After a good start, the home side were given a wake-up call after some good skill down the right-hand side allowed Jesse Curran to flash a dangerous ball across the Aberdeen penalty area. It just needed a touch from a blue shirt and the score would've been level but fortunately for The Dons there were no takers.
The response was positive, with Shinnie forcing a smart stop Jack Hamilton moments later after a clever piece of skill. Crosses into the box from wide areas appeared to be the clearest threat - both Cosgrove and May looked menacing and ready to pounce on anything.
Having been a virtual spectator all game, Joe Lewis was forced into making his first save after 40 minutes following a low drive from Nathan Ralph.
Just before the break The Dons added a thoroughly deserved second goal, through Cosgrove. The 22-year-old was quickest onto to a ball over the top and had May and McGinn alongside him for company but clearly full of confidence the striker decided to go it alone blasting his shot through the legs of Hamilton at a relatively tight angle to give The Dons a 2-0 lead at the break.
Half-Time: Aberdeen 2-0 Dundee
The Dons came out for the second half hoping to continue the momentum they gained from the first and five minutes in the home side had a third. More poor Dundee defending allowed Andy Considine to wander free into an acre of space and nod in McGinn's out-swinging corner, putting the game beyond all doubt.
Another five minutes later and three had become four. McGinn again caused havoc down the left-hand-side, combining with May before picking out the arriving McLennan. Running at pace the winger did well to compose himself and calmly slot home.
With one eye clearly on the upcoming visits of Hearts and Celtic, McInnes began to ring the changes - the first of which saw Stevie May make way for Dom Ball just after the hour mark.
The visitors did pull one back through Calvin Miller after an efficient move. Miller took the shot early and fired low past Lewis into the bottom corner, but it was far too little to late for the visitors.
James Wilson came on to replace McGinn with twenty minutes left to play.
The Dons were getting a lot of joy down the left-hand-side, McLennan won a corner after a delivery into the box which caused chaos and deflected out off a blue shirt for another corner. Shinnie's delivery was met by Considine again who forced a brilliant point-blank save from Hamilton. The keeper parried up and into the danger area and Considine reacted quickest and made sure with his second attempt nodding home for his second and Aberdeen's fifth on the night.
Cosgrove received a standing ovation after he was replaced by Forrester with fifteen minutes left on the clock. The Dons showed no signs of letting up and continued to push for a sixth but it wasn't to be and Andy Considine, unfortunately, couldn't complete his hat-trick.
It was a thoroughly pleasing night for The Dons who now go into the next two home games either side of Christmas just one-point off the top.