while Loop isn't running, or not doing what I expect it to.

I've been wracking my head over this for several hours, I can't figure out why this won't work. No matter what I seem to try, this why loop will only go through once. I'm using a platformer-style movement system in just X and Y and I want to add a "dash" functionality so that the player can perform a quick burst forward or backward. If you've played the game Rogue Legacy, the dash in that game is exactly what I'm trying to replicate.

Here's the problem code:

     void Dash(int LeftRight){
         if(canDash){
             float dashStep = Time.time;    //record the current time
             moveDirection.x = 10*LeftRight; //LeftRight is either -1 or 1, -1 for left movement 1 for right movement
             
             while(Time.time-dashStep >= 1.0F){
                 Debug.Log("Moved"); //this never fires?
                 controller.Move(moveDirection*Time.deltaTime);                    
             }
             
             canDash = false;
             dashCooldownTimer = Time.time;            
 }

Here's the full code:

 using UnityEngine;
 using System.Collections;
     
 public class Movement2d : MonoBehaviour {
     
     public float speed = 3.0F;
     public float jumpSpeed = 6.0F;
     public float playerGravity = 20.0F;
     public float doubleJumpPowerDamp = 1.0F;
 
     public float dashCooldown = 5.0F;    
     private Vector3 moveDirection = Vector3.zero;
     private bool doubleJump = false;
     private bool canDash = true;
     private float dashCooldownTimer;
     private CharacterController controller;
     //private int jumpTimer = 0;
     
     void Start () {
         controller = GetComponent<CharacterController>();        
     }
     
     // Update is called once per frame
     void Update () {
         
         if(controller.isGrounded) {
             
             //Left/Right Movement
             moveDirection = new Vector3(Input.GetAxis("Horizontal"), 0, 0);
             moveDirection = transform.TransformDirection(moveDirection);
             moveDirection *= speed;
             
             //Jump
             if(Input.GetKey(KeyCode.W) || Input.GetKey(KeyCode.UpArrow)){
                 
                 moveDirection.y = jumpSpeed;
             }
             if(moveDirection.y == 0){
                 doubleJump = true;
             }
             
             //Dash    
             if(Input.GetKeyDown(KeyCode.E)){
                 Dash (1);    
             }
             
             if(Input.GetKeyDown(KeyCode.Q)){
                 Dash (-1);                            
             }
             
             //Dash Cooldown Reset
             if(!canDash){
                 if(Time.time - dashCooldownTimer >= dashCooldown){
                     canDash = true;
                 }
             }
             
         }
         
         //Allow movement back and forth mid-air & double jumping
         else if(!controller.isGrounded && Mathf.Abs(moveDirection.x)<jumpSpeed) {
             moveDirection.x = Input.GetAxis("Horizontal") * (jumpSpeed*0.8F); //Can move left or right in the air at 80% speed
         
             //Double Jump
             if((Input.GetKeyDown(KeyCode.W) || Input.GetKeyDown(KeyCode.UpArrow)) && doubleJump==true && !controller.isGrounded){
                 moveDirection.y = jumpSpeed-doubleJumpPowerDamp; //Double Jump "strength". 0 makes double jump same as first jump
                 doubleJump = false;
             }
                 
             //Dash    
             if(Input.GetKeyDown(KeyCode.E) && !controller.isGrounded){
                 Dash (1);                    
             }
             
             if(Input.GetKeyDown(KeyCode.Q) && !controller.isGrounded){
                 Dash (-1);    
             }
         }
         
         //Rotate left or right based on movement
         if(moveDirection.x > 0)
             transform.localScale =  new Vector3(1, 1, 1);
         else if(moveDirection.x < 0)
             transform.localScale =  new Vector3(-1, 1, 1);
         
         moveDirection.z = 0; //Lock the Z position of the player.
         moveDirection.y -= playerGravity * Time.deltaTime; //Apply gravity to the player
         controller.Move(moveDirection * Time.deltaTime);  //Move the player
     }
         
     void Dash(int LeftRight){
         if(canDash){
             float dashStep = Time.time;    
             moveDirection.x = 10*LeftRight;
             
             while(Time.time-dashStep >= 1.0F){
                 Debug.Log("Moved");
                 controller.Move(moveDirection*Time.deltaTime);                    
             }
             
             canDash = false;
             dashCooldownTimer = Time.time;
         }
     }    
     
 }