material-design-icons/content/svg/design/ic_add_48px.svg

<svg xmlns="http://www.w3.org/2000/svg" width="48" height="48" viewBox="0 0 48 48">
    <path d="M38 26h-12v12h-4v-12h-12v-4h12v-12h4v12h12v4z"/>
    <path d="M0 0h48v48h-48z" fill="none"/>
</svg>