All Grain Flavor question

I created an amber ale recipe. I was going for a moderate grain flavor at the beginning and finishing with a smooth hop flavor. I wanted the two to be distinct on the pallate. When I first brewed my recipe it was exactly that. After three weeks in primary and then a few days in the keg, it was AWSOME! However, after time the flavors slowly mellowed and now there is no distinction. It is still good, but not what I was looking for and not as good as when it was still "Green". Weird I know, but I got what I wanted and then it went away.

Is there any way I can get the distinct flavors to stick and not age out?

here is the recipe.

First Amber Ale

A ProMash Recipe Report

BJCP Style and Style Guidelines
-------------------------------

10-B American Ale, American Amber Ale

Min OG: 1.045 Max OG: 1.060
Min IBU: 25 Max IBU: 48
Min Clr: 10 Max Clr: 17 Color in SRM, Lovibond

Recipe Specifics
----------------

Batch Size (Gal): 5.50 Wort Size (Gal): 5.50
Total Grain (Lbs): 12.25
Anticipated OG: 1.059 Plato: 14.57
Anticipated SRM: 12.0
Anticipated IBU: 29.9
Brewhouse Efficiency: 75 %
Wort Boil Time: 60 Minutes

Pre-Boil Amounts
----------------

Evaporation Rate: 15.00 Percent Per Hour
Pre-Boil Wort Size: 6.47 Gal
Pre-Boil Gravity: 1.050 SG 12.47 Plato

Grain/Extract/Sugar

% Amount Name Origin Potential SRM
-----------------------------------------------------------------------------
8.2 1.00 lbs. Crystal 80L 1.033 80
81.6 10.00 lbs. Pale Malt(2-row) America 1.036 2
4.1 0.50 lbs. Biscuit Malt Belgium 1.035 24
4.1 0.50 lbs. Carafoam U.S. 1.033 2
2.0 0.25 lbs. Honey Malt Canada 1.030 18

Potential represented as SG per pound per gallon.


Hops

Amount Name Form Alpha IBU Boil Time
-----------------------------------------------------------------------------
1.00 oz. Cascade Whole 5.75 22.4 60 min.
0.50 oz. Cascade Whole 5.75 5.7 30 min.
0.50 oz. Cascade Whole 5.75 1.9 5 min.


Yeast
-----
wyeast 1056 american ale

did you dry hop any of your hops?

nope. just did what is on the schedule

I was gonna say dry hop as well. I know exactly what you mean, and i'm gonna start dry hopping select brews soon to achieve that distinct hoppiness.