Gain a shinecharge running right-to-left to obtain temporary blue. Then jump and morph, bouncing through the tunnel above, with the crumble block already broken. Unmorph when exiting the tunnel, and chain temporary blue into the next room.

Requires:

{
  "notable": "Return Through Crumble Blocks"
}
{
  "obstaclesCleared": [
    "C"
  ]
}
{
  "canShineCharge": {
    "usedTiles": 16,
    "openEnd": 0
  }
}
"canTrickySpringBallBounce"
"canChainTemporaryBlue"
"canInsaneJump"

Exit condition:

{
  "leaveWithTemporaryBlue": {}
}

Unlocks doors:

{"types":["ammo"],"requires":[]}

The Crumble Block next to the Power Bomb Blocks does not respawn, so it's possible to enter from this door, grab the items, and return without breaking the Power Bomb blocks.

Requires:

{
  "notable": "Return Through Crumble Blocks"
}
"canMidAirMorph"
{
  "obstaclesCleared": [
    "C"
  ]
}