Rubik Madness

Only the cubes between corners at the side having stickers in two faces.

A tyipical cubes have 8 corners and 12 sides. For $3\times3\times3$ Rubik's cube there is only one cube in between the two corner cubes at each side. This yields the number of cubes having sticker on two side be $12\times1 =\boxed{12}$ .

For a general $N\times N\times N$ Rubik's cube, there are $(N-2)$ cubes in between the two corner cubes at each sides. Therefore the general formula is: $\boxed{12(N-2)}$

I seriously just looked at the picture and counted.

Each original face has 4 cubes with 2 stickers on. Therefore, as half of these are shared, you get answer = (4 x 6)/2 = 12

4 squares on the top layer. 4 squares on the middle layer. 4 squares on the bottom layer.

4x3=12

Little offtop:

Let me see that one can't break up a Rubik's Cube into $3^3$ cubes, because there's no middle cube. There is a mechanism inside, not a single cube, therefore we can break it up into $26$ single cubes.