Add your text in white with a black background. When you have decided on a word, rasterize your text by right clicking with the text tool and choosing"rasterize."

Next go to Filter > Blur > Gaussian Blur. I chose a potency of 4.

Next choose Filter > Pixelate > Mosaic

Next choose Filter > Sharpen > Sharpen. Sharpen it a few more times until the cubes are to your liking by pressing Ctrl+F to repeat the filter.

Create a new layer with type "color" and run a gradient of your choice across your image. I wanted an Ice-cube look, so I went with blue! Here is how mine turned out.