The Mariana Trench is actually a crescent shape from above, and its profile is like an upside-down triangle. For the ease of calculation, I’ll pretend that it’s actually a rectangular prism.

From trivia night, I know the deepest point is about 11km below sea level. However, the ocean basin is about 4km below sea level, so the actual depth of the trench is probably around 11-4=7km.

I’ll guess based on the overhead map image that the crescent shape is around 2000km in length and about 50km in width. The volume is then about 7×50×2000=700,000km³

Everytime I make a full dish of lasagna, I use about 2 standard 24oz jars of marinara, or 1 litre.

700,000km³ is 7×10^17 litres, so I could make 7×10^17 or seven hundred quadrillion lasagnas.