1 - right-click the Panel
2 - click on Add to Panel
3 - Scroll down to the bottom
4 - On the Utilities section, you'll find these icons:
Linux Mint Menu (default)
Play with them, adding/removing them & choose the one you like most (first remove the default (right-click on it > Remove from Panel), then move your new menu icon to the far left (right-click > move).
Sorry, but that's the way it is.