[Mean]

Brackets are not needed here, nor they will not change anything, isn't it logic that you can use it like this:

pawn Код:

dcmd_something( playerid, params[ ] ) 
    return SendClientMessage( playerid, 0xAAAAAA, "abcd" );

If you can use this, you can also use:

pawn Код:

dcmd_donut(playerid,params[])
    SetPVarInt(playerid, "donutHealth", SetTimerEx("donutHealth", 1000, true, "i", playerid));

So, probbably, not a bracket problem.
The real problem was you need to use return.

pawn Код:

dcmd_donut(playerid,params[])
    SetPVarInt(playerid, "donutHealth"); return SetTimerEx("donutHealth", 1000, true, "i", playerid);