I have a good friend who is a piano teacher. She wanted music related cookies to share with her students and families during their spring piano recital. We discussed possible designs, and I immediately thought of doing a 3D piano keys cookie.
I googled piano keys and found this terrific photo. I printed the photo out and cut out a portion with only three white keys and two black keys. I used this "template" to help me divide up the rectangular cookie shape I cut out that was approximately the same size.
Before baking, use a cake tester to divide the dough evenly into three white keys. Push an actual dividing line between the "keys" with the cake tester. (see photo below)
Next, cut out long thin stips of dough (rolled very thin) and lay them on top of the cookie in the spots that correspond with the black keys on the template. (see photo below)
Trim off the top of the added dough strips to make all the keys straight across on top.
Bake and cool the cookies as usual.
Outline and flood the white keys. Outline and flood the elevated black keys. (see photo below)
Such fun cookies to celebrate a piano recital. :)