Where's the nuttiness coming from?

I brewed my first batch of all grain 2 weeks ago. I took a gravity reading a couple days ago and noticed a strong nutty flavor in the finish on the back of my palate. I'm wondering if this will mellow out with the final stage of fermenting and bottle conditioning. What ingredient is bringing out this flavor? I'm using a kolsch yeast but treating it like an ale and not lagering.
5 gal batch.
6# 2 row
3# Munich malt
.75# honey malt
.4# crystal 20
Centennial an Amarillo hops
Wyeast kolsch 2565 yeast
I pitched yeast fairly warm at 75F but brought temp down to 65 within 2 days.

Well, the first couple of days is where a lot of the flavor of fermentation come from, so it's possible that the flavor is due to pitching temps. However, every beer typically gets better with age (except IPAs).

Probably the munich malt or overcrushed fresh grains. The grainy-nutty flavor in your roasted grains can settle out a bit with some cold conditioning for about 30 days. The flavor should improve with time and some cold.

Looking at that yeast I would probably have pitched and tried for about 60 degrees for the first 5 days or so.

Given that I would say that I find most of mine to taste a LOT different between the fermentation stage and when it is done. Case in point is my Ebony IPA at a week in the keg I was a bit disappointed, 3 days later it is very good.

Just an update. This has been in the bottle for two weeks and I have tried it a couple times. The nuttiness has greatly mellowed out and is now more bready, but very slight only on the finish. Still haven't determined which ingredient was responsible, but its turning out to be a great beer.