What is the best way to make the B shape in this gif? I am modelling a set of stairs:

and wish to turn them into a high polygon model to resemble this with clear spaces between the bricks and all bricks to be of the same size:

I saw the below gif from Rigid Body Dynamic Animation Problem but no way to reproduce the B it so that the model is made up of cubes with the edges of the model being smoothed or curved to fit the original mesh.

So far all I have is this built from arrays (I am aware I'll need many more) from this tutorial Destroying any object into cubes but my blender locks up for quite a long time and has yet to finish processing it:

Any suggestions?
In the end, I decided to use Destroying any object into cubes and breaking the model into a more simple geometry for my computer to handle.