A sexual act. First, a penis-owner uses waffle batter as lube to penetrate a vagina-owner without a condom, releasing their load inside their partner. The vagina-owner then squats over a waffle iron to create a delicious breakfast for them to eat.
A Mac Waffle is when you get so frustrated with your Apple laptop that you take a shit on your keyboard and close the laptop. Then, when opened again, you have a flattened turd with the impressions of small squares from the keyboard, giving it the likeness of a waffle.
Dude my MacBook is so frustrating. It won’t let me do anything that I have to do! I’m about to make a Mac Waffle!!