Gradle -- execute multiple commands from task

You can use the second way to declare task types on gradle.

task senchaCmdBuild {
  doLast {
    exec {
      workingDir 'src/main/app/MYAPP'
      commandLine 'cmd', 'c', 'sencha app build'
    }
    exec {
      workingDir 'src/main/app/MYOTHERAPP'
      commandLine 'cmd', 'c', 'sencha app build'
    }
  }
}

You need put the exec method in doLast in order to be executed only on execution flow

It's impossible to configure (run) multiple commands for the task of type Exec. commandLine it's just a setter - the last one wins. If you need to run multiple commands the best idea is to implement multiple tasks as @RaGe suggested in the comment or to write a custom task and use groovy's native mechanisms - execute method.