write(), printf(), and function references in C

Question

A few questions about this simple scenario:

#include <unistd.h>
#include <stdio.h>

void empty(){};

int main()
{
    printf("%p\t%lu\n", empty, sizeof(empty));
    write(1, empty, 100);

    return 0;
}

What exactly is happening when I use the function's name as a reference?

It shows size of one but printf still treats it as a pointer and yet a void pointer is of size 8. Additionally, onto the write function:

Essentially I want to replicate the printf %p writing the value of a memory address rather than the value at that address mainly to get a better handle on how this all works :^)

Thanks!