From the bottom of the sand, shoot upwards to break the block then Shinespark up. To use a flash suit in deep sand: vertically - quickly roll the directional inputs from forward to up and jump. diagonally, with minimal horizontal speed - while holding angle, quickly tap forward then press and hold jump. Alternatively, to save Energy, shoot the block without falling into the sand, then reposition and spark up left. This can be done with a midair unmorph then shoot up, or from shooting up from the sand surface then quickly spin jumping off in order not to sink.

Requires:

"canPlayInSand"
"canHeroShot"
{
  "useFlashSuit": {}
}
{
  "or": [
    {
      "shinespark": {
        "frames": 27,
        "excessFrames": 5
      }
    },
    {
      "and": [
        "canTrickyCarryFlashSuit",
        {
          "shinespark": {
            "frames": 18,
            "excessFrames": 3
          }
        }
      ]
    }
  ]
}