How do I get rid of the one SPI clock cycle delay between each spi.write command?

#include "mbed.h"

SPI spi(p5, p6, p7); //mosi, miso, sclk
DigitalOut cs_n(p8);
DigitalOut led1(LED1);

Serial pc(USBTX, USBRX); // tx, rx

int main() {
  
    // Chip must be deselected
    cs_n = 1;
    led1 = 0;
 
    // Setup the spi for 8 bit data, high steady state clock,
    // second edge capture, with a 1MHz clock rate
    spi.format(16,3);
    spi.frequency(1000000);
    wait(1);
    while (1) {
    // Select the device by seting chip select low
       
       cs_n = 0;
   
       int Num1=spi.write (0x00);  // send the address location of 0x0010 and expect to read the content to SerialNum  
       int Num2=spi.write (0x00);
       int Num3=spi.write (0x00);  
       int Num4=spi.write (0x00);       
       
       cs_n = 1; 
       
       printf ("Read Value = 0x %2X %2X %2X %2X  \n\n", Num1, Num2,Num3,Num4);   // re-check the content again.
       wait_ms(50);
    }
}

SPI spi(p5,p6,p7);
spi.frequency(1000000);
LPC_SSP1->CR0 |= 0x10;        // Switch to TI mode

main() {
            while (!(LPC_SSP1->SR & 2));   //if TNF-Bit = 0 (FIFO full) then wait; TNF-Bit is Bit 1 in SSPxSR
            LPC_SSP1->DR = (0xff);
            while (!(LPC_SSP1->SR & 2));   //if TNF-Bit = 0 (FIFO full) then wait; TNF-Bit is Bit 1 in SSPxSR
            LPC_SSP1->DR = (0x00);
            while (!(LPC_SSP1->SR & 2));   //if TNF-Bit = 0 (FIFO full) then wait; TNF-Bit is Bit 1 in SSPxSR
            LPC_SSP1->DR = (0x00);
}
//untested