I've often wondered about how to get more of that wonderful aroma in the beer, but unfortunately, I don't think adding a few oz of grain (cf. dry hopping) will add any appreciable difference, considering that the aroma that is there has been produced by several pounds of grain. (Although the wort was boiled which may drive off aromas.)
Just thinking aloud, you might get closer to your goal of more malt aroma by saving some of the wort and boiling it in a sealed environment, and then leaving to cool, in the same spirit that a hopback is used with a chiller to capture hop aroma. Although boiling wort is normally in a open environment to allow Dimethyl Sulphides to evaporate, we are only talking a quart or two, so we can hope this small amount isn't above the taste threshold.
On a more practical level, you can get more malt flavour and aroma to come through by adjusting the recipe:
- add chlorides (up to 50ppm) to emphasize the malt
- use less hops to avoid masking the malt flavour and aroma
- add malts that have a stronger aroma or malt character: munich is a good neutral choice since the character is pure malt, but other speciality malts can be added such as amber, biscuit, victory, melanoiden and in smaller quantities, coffee and chocolate malt to give other aromas as desired.
And just to finish on a wild guess, perhaps cold storage after fermentation may also help preserve more of the aroma, in the same way hop aromas are preserved through cold storage.