>Have no idea why im not getting this, it seems simple
>enough.

Right. If you cut 4 of something (sausages, say) put side by side so that you are able to cut all 4 with one cut, you get 8 pieces.

Unquestionably, you can cut the pie into 4 pieces with 2 cuts. Imagine now the pie put on a side, so that all 4 pieces become exposed to a vertical cut. Do it.

The 8 pieces you obtain are not exactly what one would expect: 4 come from the bottom of the pie, 4 from the top. The latter carry all the toppings and, in all likelihood, are more desirable. The former may be less hazardous to one's health, though.